<?xml version="1.0" encoding="us-ascii"?>
<!-- Created by Merrill Corporation -->
<!-- Generated by Fujitsu Interstage XWand B0160 -->
<linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns="http://www.xbrl.org/2003/linkbase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:uthr="http://www.unither.com/20111231" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:xlink="http://www.w3.org/1999/xlink">
  <roleRef roleURI="http://www.unither.com/role/StatementOfStockholdersEquity" xlink:type="simple" xlink:href="uthr-20111231.xsd#StatementOfStockholdersEquity" />
  <roleRef roleURI="http://www.unither.com/role/BalanceSheet" xlink:type="simple" xlink:href="uthr-20111231.xsd#BalanceSheet" />
  <roleRef roleURI="http://www.unither.com/role/CashFlows" xlink:type="simple" xlink:href="uthr-20111231.xsd#CashFlows" />
  <roleRef roleURI="http://www.unither.com/role/StatementOfIncome" xlink:type="simple" xlink:href="uthr-20111231.xsd#StatementOfIncome" />
  <roleRef roleURI="http://www.unither.com/role/StatementOfStockholdersEquityCalc2" xlink:type="simple" xlink:href="uthr-20111231.xsd#StatementOfStockholdersEquityCalc2" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureComprehensiveIncomeDetails" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureComprehensiveIncomeDetails" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureInventoriesDetails" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureInventoriesDetails" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureSupplementalExecutiveRetirementPlanDetails" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureSupplementalExecutiveRetirementPlanDetails" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureGoodwillAndOtherIntangibleAssetsDetails" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails2" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureGoodwillAndOtherIntangibleAssetsDetails2" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureMarketableInvestmentsDetails" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureMarketableInvestmentsDetails" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureMarketableInvestmentsDetails2" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureMarketableInvestmentsDetails2" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureMarketableInvestmentsDetails3" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureMarketableInvestmentsDetails3" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureFairValueMeasurementsDetails" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureFairValueMeasurementsDetails" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureShareTrackingAwardsPlanDetails2" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureShareTrackingAwardsPlanDetails2" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureStockholdersEquityDetails" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureStockholdersEquityDetails" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureDebtDetails" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureDebtDetails" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureSaleOfBusinessDetails2" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureSaleOfBusinessDetails2" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureSaleOfBusinessDetails" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureSaleOfBusinessDetails" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureMarketableInvestmentsDetails4" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureMarketableInvestmentsDetails4" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureAccruedExpensesDetails" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureAccruedExpensesDetails" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureIncomeTaxesDetails" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureIncomeTaxesDetails" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureIncomeTaxesDetails2" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureIncomeTaxesDetails2" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureIncomeTaxesDetails3" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureIncomeTaxesDetails3" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureDebtDetails3" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureDebtDetails3" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureSummaryOfSignificantAccountingPoliciesDetails" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails2" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureSummaryOfSignificantAccountingPoliciesDetails2" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails3" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureSummaryOfSignificantAccountingPoliciesDetails3" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureCommitmentsAndContingenciesDetails" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureCommitmentsAndContingenciesDetails" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureEmployeeBenefitPlansDetails" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureEmployeeBenefitPlansDetails" />
  <roleRef roleURI="http://www.unither.com/role/DisclosureSegmentInformationDetails" xlink:type="simple" xlink:href="uthr-20111231.xsd#DisclosureSegmentInformationDetails" />
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureComprehensiveIncomeDetails">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="ComprehensiveIncomeNetOfTax" xlink:title="ComprehensiveIncomeNetOfTax" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:title="NetIncomeLossAvailableToCommonStockholdersBasic" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTax" xlink:to="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:title="calculation: ComprehensiveIncomeNetOfTax to NetIncomeLossAvailableToCommonStockholdersBasic" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" xlink:label="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" xlink:title="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTax" xlink:to="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" xlink:title="calculation: ComprehensiveIncomeNetOfTax to OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" xlink:label="OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" xlink:title="OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTax" xlink:to="OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" xlink:title="calculation: ComprehensiveIncomeNetOfTax to OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" use="optional" order="5.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax" xlink:label="OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax" xlink:title="OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTax" xlink:to="OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax" xlink:title="calculation: ComprehensiveIncomeNetOfTax to OtherComprehensiveIncomeDefinedBenefitPlanNetPriorServiceCostsCreditArisingDuringPeriodNetOfTax" use="optional" order="3.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax" xlink:label="OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax" xlink:title="OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTax" xlink:to="OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax" xlink:title="calculation: ComprehensiveIncomeNetOfTax to OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax" use="optional" order="4.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails2">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:label="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:title="FiniteLivedIntangibleAssetsFutureAmortizationExpense" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearOne" xlink:label="FutureAmortizationExpenseYearOne" xlink:title="FutureAmortizationExpenseYearOne" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseYearOne" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseYearOne" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearTwo" xlink:label="FutureAmortizationExpenseYearTwo" xlink:title="FutureAmortizationExpenseYearTwo" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseYearTwo" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseYearTwo" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearThree" xlink:label="FutureAmortizationExpenseYearThree" xlink:title="FutureAmortizationExpenseYearThree" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseYearThree" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseYearThree" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearFour" xlink:label="FutureAmortizationExpenseYearFour" xlink:title="FutureAmortizationExpenseYearFour" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseYearFour" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseYearFour" use="optional" order="4.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearFive" xlink:label="FutureAmortizationExpenseYearFive" xlink:title="FutureAmortizationExpenseYearFive" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseYearFive" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseYearFive" use="optional" order="5.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseAfterYearFive" xlink:label="FutureAmortizationExpenseAfterYearFive" xlink:title="FutureAmortizationExpenseAfterYearFive" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseAfterYearFive" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseAfterYearFive" use="optional" order="6.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureStockholdersEquityDetails">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="WeightedAverageNumberOfDilutedSharesOutstanding" xlink:title="WeightedAverageNumberOfDilutedSharesOutstanding" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="WeightedAverageNumberOfSharesOutstandingBasic" xlink:title="WeightedAverageNumberOfSharesOutstandingBasic" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="WeightedAverageNumberOfDilutedSharesOutstanding" xlink:to="WeightedAverageNumberOfSharesOutstandingBasic" xlink:title="calculation: WeightedAverageNumberOfDilutedSharesOutstanding to WeightedAverageNumberOfSharesOutstandingBasic" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToConversionOfDebtSecurities" xlink:label="IncrementalCommonSharesAttributableToConversionOfDebtSecurities" xlink:title="IncrementalCommonSharesAttributableToConversionOfDebtSecurities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="WeightedAverageNumberOfDilutedSharesOutstanding" xlink:to="IncrementalCommonSharesAttributableToConversionOfDebtSecurities" xlink:title="calculation: WeightedAverageNumberOfDilutedSharesOutstanding to IncrementalCommonSharesAttributableToConversionOfDebtSecurities" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:label="IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:title="IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="WeightedAverageNumberOfDilutedSharesOutstanding" xlink:to="IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:title="calculation: WeightedAverageNumberOfDilutedSharesOutstanding to IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToCallOptionsAndWarrants" xlink:label="IncrementalCommonSharesAttributableToCallOptionsAndWarrants" xlink:title="IncrementalCommonSharesAttributableToCallOptionsAndWarrants" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="WeightedAverageNumberOfDilutedSharesOutstanding" xlink:to="IncrementalCommonSharesAttributableToCallOptionsAndWarrants" xlink:title="calculation: WeightedAverageNumberOfDilutedSharesOutstanding to IncrementalCommonSharesAttributableToCallOptionsAndWarrants" use="optional" order="4.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureInventoriesDetails">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InventoryNet" xlink:label="InventoryNet" xlink:title="InventoryNet" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InventoryRawMaterialsNetOfReserves" xlink:label="InventoryRawMaterialsNetOfReserves" xlink:title="InventoryRawMaterialsNetOfReserves" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="InventoryNet" xlink:to="InventoryRawMaterialsNetOfReserves" xlink:title="calculation: InventoryNet to InventoryRawMaterialsNetOfReserves" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InventoryWorkInProcessNetOfReserves" xlink:label="InventoryWorkInProcessNetOfReserves" xlink:title="InventoryWorkInProcessNetOfReserves" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="InventoryNet" xlink:to="InventoryWorkInProcessNetOfReserves" xlink:title="calculation: InventoryNet to InventoryWorkInProcessNetOfReserves" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InventoryFinishedGoodsNetOfReserves" xlink:label="InventoryFinishedGoodsNetOfReserves" xlink:title="InventoryFinishedGoodsNetOfReserves" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="InventoryNet" xlink:to="InventoryFinishedGoodsNetOfReserves" xlink:title="calculation: InventoryNet to InventoryFinishedGoodsNetOfReserves" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherInventoryNetOfReserves" xlink:label="OtherInventoryNetOfReserves" xlink:title="OtherInventoryNetOfReserves" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="InventoryNet" xlink:to="OtherInventoryNetOfReserves" xlink:title="calculation: InventoryNet to OtherInventoryNetOfReserves" order="4.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureMarketableInvestmentsDetails4">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesNetCarryingAmount" xlink:label="HeldToMaturitySecuritiesDebtMaturitiesNetCarryingAmount" xlink:title="HeldToMaturitySecuritiesDebtMaturitiesNetCarryingAmount" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount" xlink:label="HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount" xlink:title="HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="HeldToMaturitySecuritiesDebtMaturitiesNetCarryingAmount" xlink:to="HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount" xlink:title="calculation: HeldToMaturitySecuritiesDebtMaturitiesNetCarryingAmount to HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_HeldToMaturitySecuritiesDebtMaturitiesInOneYearThroughTwoYearsNetCarryingAmount" xlink:label="HeldToMaturitySecuritiesDebtMaturitiesInOneYearThroughTwoYearsNetCarryingAmount" xlink:title="HeldToMaturitySecuritiesDebtMaturitiesInOneYearThroughTwoYearsNetCarryingAmount" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="HeldToMaturitySecuritiesDebtMaturitiesNetCarryingAmount" xlink:to="HeldToMaturitySecuritiesDebtMaturitiesInOneYearThroughTwoYearsNetCarryingAmount" xlink:title="calculation: HeldToMaturitySecuritiesDebtMaturitiesNetCarryingAmount to HeldToMaturitySecuritiesDebtMaturitiesInOneYearThroughTwoYearsNetCarryingAmount" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesFairValue" xlink:label="HeldToMaturitySecuritiesDebtMaturitiesFairValue" xlink:title="HeldToMaturitySecuritiesDebtMaturitiesFairValue" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue" xlink:label="HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue" xlink:title="HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="HeldToMaturitySecuritiesDebtMaturitiesFairValue" xlink:to="HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue" xlink:title="calculation: HeldToMaturitySecuritiesDebtMaturitiesFairValue to HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_HeldToMaturitySecuritiesDebtMaturitiesInOneYearThroughTwoYearsFairValue" xlink:label="HeldToMaturitySecuritiesDebtMaturitiesInOneYearThroughTwoYearsFairValue" xlink:title="HeldToMaturitySecuritiesDebtMaturitiesInOneYearThroughTwoYearsFairValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="HeldToMaturitySecuritiesDebtMaturitiesFairValue" xlink:to="HeldToMaturitySecuritiesDebtMaturitiesInOneYearThroughTwoYearsFairValue" xlink:title="calculation: HeldToMaturitySecuritiesDebtMaturitiesFairValue to HeldToMaturitySecuritiesDebtMaturitiesInOneYearThroughTwoYearsFairValue" use="optional" order="2.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/StatementOfStockholdersEquityCalc2">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="ComprehensiveIncomeNetOfTax" xlink:title="ComprehensiveIncomeNetOfTax" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:title="NetIncomeLossAvailableToCommonStockholdersBasic" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTax" xlink:to="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:title="calculation: ComprehensiveIncomeNetOfTax to NetIncomeLossAvailableToCommonStockholdersBasic" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" xlink:label="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" xlink:title="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTax" xlink:to="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" xlink:title="calculation: ComprehensiveIncomeNetOfTax to OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" xlink:label="OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" xlink:title="OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTax" xlink:to="OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" xlink:title="calculation: ComprehensiveIncomeNetOfTax to OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent" xlink:label="OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent" xlink:title="OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="ComprehensiveIncomeNetOfTax" xlink:to="OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent" xlink:title="calculation: ComprehensiveIncomeNetOfTax to OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent" use="optional" order="4.0" weight="-1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/BalanceSheet">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_Assets" xlink:label="Assets" xlink:title="Assets" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="AssetsCurrent" xlink:title="AssetsCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="AssetsCurrent" xlink:title="calculation: Assets to AssetsCurrent" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="CashAndCashEquivalentsAtCarryingValue" xlink:title="CashAndCashEquivalentsAtCarryingValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="CashAndCashEquivalentsAtCarryingValue" xlink:title="calculation: AssetsCurrent to CashAndCashEquivalentsAtCarryingValue" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldToMaturitySecuritiesCurrent" xlink:label="HeldToMaturitySecuritiesCurrent" xlink:title="HeldToMaturitySecuritiesCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="HeldToMaturitySecuritiesCurrent" xlink:title="calculation: AssetsCurrent to HeldToMaturitySecuritiesCurrent" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="AccountsReceivableNetCurrent" xlink:title="AccountsReceivableNetCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="AccountsReceivableNetCurrent" xlink:title="calculation: AssetsCurrent to AccountsReceivableNetCurrent" use="optional" order="3.0" weight="1.0" xbrldt:closed="true" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:label="OtherAssetsCurrent" xlink:title="OtherAssetsCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="OtherAssetsCurrent" xlink:title="calculation: AssetsCurrent to OtherAssetsCurrent" use="optional" order="4.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PrepaidExpenseCurrent" xlink:label="PrepaidExpenseCurrent" xlink:title="PrepaidExpenseCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="PrepaidExpenseCurrent" xlink:title="calculation: AssetsCurrent to PrepaidExpenseCurrent" use="optional" order="5.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InventoryNet" xlink:label="InventoryNet" xlink:title="InventoryNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="InventoryNet" xlink:title="calculation: AssetsCurrent to InventoryNet" use="optional" order="6.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxAssetsNetCurrent" xlink:label="DeferredTaxAssetsNetCurrent" xlink:title="DeferredTaxAssetsNetCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsCurrent" xlink:to="DeferredTaxAssetsNetCurrent" xlink:title="calculation: AssetsCurrent to DeferredTaxAssetsNetCurrent" use="optional" order="7.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RestrictedCashAndInvestmentsNoncurrent" xlink:label="RestrictedCashAndInvestmentsNoncurrent" xlink:title="RestrictedCashAndInvestmentsNoncurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="RestrictedCashAndInvestmentsNoncurrent" xlink:title="calculation: Assets to RestrictedCashAndInvestmentsNoncurrent" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_GoodwillAndOtherIntangiblesAssets" xlink:label="GoodwillAndOtherIntangiblesAssets" xlink:title="GoodwillAndOtherIntangiblesAssets" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="GoodwillAndOtherIntangiblesAssets" xlink:title="calculation: Assets to GoodwillAndOtherIntangiblesAssets" use="optional" order="4.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="PropertyPlantAndEquipmentNet" xlink:title="PropertyPlantAndEquipmentNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="PropertyPlantAndEquipmentNet" xlink:title="calculation: Assets to PropertyPlantAndEquipmentNet" use="optional" order="5.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxAssetsNetNoncurrent" xlink:label="DeferredTaxAssetsNetNoncurrent" xlink:title="DeferredTaxAssetsNetNoncurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="DeferredTaxAssetsNetNoncurrent" xlink:title="calculation: Assets to DeferredTaxAssetsNetNoncurrent" use="optional" order="6.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="OtherAssetsNoncurrent" xlink:title="OtherAssetsNoncurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="OtherAssetsNoncurrent" xlink:title="calculation: Assets to OtherAssetsNoncurrent" use="optional" order="7.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_MarketableSecuritiesNoncurrent" xlink:label="MarketableSecuritiesNoncurrent" xlink:title="MarketableSecuritiesNoncurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Assets" xlink:to="MarketableSecuritiesNoncurrent" xlink:title="calculation: Assets to MarketableSecuritiesNoncurrent" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="LiabilitiesAndStockholdersEquity" xlink:title="LiabilitiesAndStockholdersEquity" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_Liabilities" xlink:label="Liabilities" xlink:title="Liabilities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesAndStockholdersEquity" xlink:to="Liabilities" xlink:title="calculation: LiabilitiesAndStockholdersEquity to Liabilities" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="LiabilitiesCurrent" xlink:title="LiabilitiesCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Liabilities" xlink:to="LiabilitiesCurrent" xlink:title="calculation: Liabilities to LiabilitiesCurrent" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="AccountsPayableCurrent" xlink:title="AccountsPayableCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesCurrent" xlink:to="AccountsPayableCurrent" xlink:title="calculation: LiabilitiesCurrent to AccountsPayableCurrent" use="optional" order="1.0" weight="1.0" xbrldt:closed="true" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="AccruedLiabilitiesCurrent" xlink:title="AccruedLiabilitiesCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesCurrent" xlink:to="AccruedLiabilitiesCurrent" xlink:title="calculation: LiabilitiesCurrent to AccruedLiabilitiesCurrent" use="optional" order="2.0" weight="1.0" xbrldt:closed="true" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:label="OtherLiabilitiesCurrent" xlink:title="OtherLiabilitiesCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesCurrent" xlink:to="OtherLiabilitiesCurrent" xlink:title="calculation: LiabilitiesCurrent to OtherLiabilitiesCurrent" use="optional" order="4.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ConvertibleNotesPayableCurrent" xlink:label="ConvertibleNotesPayableCurrent" xlink:title="ConvertibleNotesPayableCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesCurrent" xlink:to="ConvertibleNotesPayableCurrent" xlink:title="calculation: LiabilitiesCurrent to ConvertibleNotesPayableCurrent" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LongTermNotesPayable" xlink:label="LongTermNotesPayable" xlink:title="LongTermNotesPayable" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Liabilities" xlink:to="LongTermNotesPayable" xlink:title="calculation: Liabilities to LongTermNotesPayable" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="OtherLiabilitiesNoncurrent" xlink:title="OtherLiabilitiesNoncurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Liabilities" xlink:to="OtherLiabilitiesNoncurrent" xlink:title="calculation: Liabilities to OtherLiabilitiesNoncurrent" use="optional" order="4.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ConvertibleLongTermNotesPayable" xlink:label="ConvertibleLongTermNotesPayable" xlink:title="ConvertibleLongTermNotesPayable" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Liabilities" xlink:to="ConvertibleLongTermNotesPayable" xlink:title="calculation: Liabilities to ConvertibleLongTermNotesPayable" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_TemporaryEquityRedemptionValue" xlink:label="TemporaryEquityRedemptionValue" xlink:title="TemporaryEquityRedemptionValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesAndStockholdersEquity" xlink:to="TemporaryEquityRedemptionValue" xlink:title="calculation: LiabilitiesAndStockholdersEquity to TemporaryEquityRedemptionValue" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="StockholdersEquity" xlink:title="StockholdersEquity" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LiabilitiesAndStockholdersEquity" xlink:to="StockholdersEquity" xlink:title="calculation: LiabilitiesAndStockholdersEquity to StockholdersEquity" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="PreferredStockValue" xlink:title="PreferredStockValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="PreferredStockValue" xlink:title="calculation: StockholdersEquity to PreferredStockValue" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="AdditionalPaidInCapitalCommonStock" xlink:title="AdditionalPaidInCapitalCommonStock" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="AdditionalPaidInCapitalCommonStock" xlink:title="calculation: StockholdersEquity to AdditionalPaidInCapitalCommonStock" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:title="AccumulatedOtherComprehensiveIncomeLossNetOfTax" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:title="calculation: StockholdersEquity to AccumulatedOtherComprehensiveIncomeLossNetOfTax" use="optional" order="4.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_TreasuryStockValue" xlink:label="TreasuryStockValue" xlink:title="TreasuryStockValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="TreasuryStockValue" xlink:title="calculation: StockholdersEquity to TreasuryStockValue" use="optional" order="5.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="RetainedEarningsAccumulatedDeficit" xlink:title="RetainedEarningsAccumulatedDeficit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="RetainedEarningsAccumulatedDeficit" xlink:title="calculation: StockholdersEquity to RetainedEarningsAccumulatedDeficit" use="optional" order="6.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CommonStockValue" xlink:label="CommonStockValue" xlink:title="CommonStockValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquity" xlink:to="CommonStockValue" xlink:title="calculation: StockholdersEquity to CommonStockValue" order="2.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/StatementOfStockholdersEquity">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockholdersEquityPeriodIncreaseDecrease" xlink:label="StockholdersEquityPeriodIncreaseDecrease" xlink:title="StockholdersEquityPeriodIncreaseDecrease" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="StockIssuedDuringPeriodValueStockOptionsExercised" xlink:title="StockIssuedDuringPeriodValueStockOptionsExercised" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="StockIssuedDuringPeriodValueStockOptionsExercised" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to StockIssuedDuringPeriodValueStockOptionsExercised" order="11.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation" xlink:label="AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation" xlink:title="AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation" order="12.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:title="AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" order="13.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:title="NetIncomeLossAvailableToCommonStockholdersBasic" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to NetIncomeLossAvailableToCommonStockholdersBasic" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockDividend" xlink:label="StockIssuedDuringPeriodValueStockDividend" xlink:title="StockIssuedDuringPeriodValueStockDividend" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="StockIssuedDuringPeriodValueStockDividend" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to StockIssuedDuringPeriodValueStockDividend" order="7.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" xlink:label="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" xlink:title="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" xlink:label="OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" xlink:title="OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent" xlink:label="OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent" xlink:title="OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent" use="optional" order="4.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_SharesReceivedUponSaleOfSubsidiary" xlink:label="SharesReceivedUponSaleOfSubsidiary" xlink:title="SharesReceivedUponSaleOfSubsidiary" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="SharesReceivedUponSaleOfSubsidiary" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to SharesReceivedUponSaleOfSubsidiary" order="5.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalConvertibleDebtWithConversionFeature" xlink:label="AdjustmentsToAdditionalPaidInCapitalConvertibleDebtWithConversionFeature" xlink:title="AdjustmentsToAdditionalPaidInCapitalConvertibleDebtWithConversionFeature" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="AdjustmentsToAdditionalPaidInCapitalConvertibleDebtWithConversionFeature" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to AdjustmentsToAdditionalPaidInCapitalConvertibleDebtWithConversionFeature" use="optional" order="8.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_AdjustmentsToAdditionalPaidInCapitalConvertibleDebtHedgeAndWarrantsNet" xlink:label="AdjustmentsToAdditionalPaidInCapitalConvertibleDebtHedgeAndWarrantsNet" xlink:title="AdjustmentsToAdditionalPaidInCapitalConvertibleDebtHedgeAndWarrantsNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="AdjustmentsToAdditionalPaidInCapitalConvertibleDebtHedgeAndWarrantsNet" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to AdjustmentsToAdditionalPaidInCapitalConvertibleDebtHedgeAndWarrantsNet" use="optional" order="9.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_StockIssuedDuringPeriodValueConversionOfConvertibleSecuritiesAndSharesReceivedThroughHedgeExercise" xlink:label="StockIssuedDuringPeriodValueConversionOfConvertibleSecuritiesAndSharesReceivedThroughHedgeExercise" xlink:title="StockIssuedDuringPeriodValueConversionOfConvertibleSecuritiesAndSharesReceivedThroughHedgeExercise" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="StockIssuedDuringPeriodValueConversionOfConvertibleSecuritiesAndSharesReceivedThroughHedgeExercise" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to StockIssuedDuringPeriodValueConversionOfConvertibleSecuritiesAndSharesReceivedThroughHedgeExercise" order="6.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod" xlink:label="TreasuryStockValueAcquiredCostMethod" xlink:title="TreasuryStockValueAcquiredCostMethod" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockholdersEquityPeriodIncreaseDecrease" xlink:to="TreasuryStockValueAcquiredCostMethod" xlink:title="calculation: StockholdersEquityPeriodIncreaseDecrease to TreasuryStockValueAcquiredCostMethod" use="optional" order="10.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:label="StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:title="StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:title="StockIssuedDuringPeriodSharesStockOptionsExercised" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:to="StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:title="calculation: StockIssuedDuringPeriodSharesPeriodIncreaseDecrease to StockIssuedDuringPeriodSharesStockOptionsExercised" order="4.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:label="StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:title="StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:to="StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:title="calculation: StockIssuedDuringPeriodSharesPeriodIncreaseDecrease to StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_SharesReceivedUponSaleOfSubsidiaryShares" xlink:label="SharesReceivedUponSaleOfSubsidiaryShares" xlink:title="SharesReceivedUponSaleOfSubsidiaryShares" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:to="SharesReceivedUponSaleOfSubsidiaryShares" xlink:title="calculation: StockIssuedDuringPeriodSharesPeriodIncreaseDecrease to SharesReceivedUponSaleOfSubsidiaryShares" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockSplits" xlink:label="StockIssuedDuringPeriodSharesStockSplits" xlink:title="StockIssuedDuringPeriodSharesStockSplits" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="StockIssuedDuringPeriodSharesPeriodIncreaseDecrease" xlink:to="StockIssuedDuringPeriodSharesStockSplits" xlink:title="calculation: StockIssuedDuringPeriodSharesPeriodIncreaseDecrease to StockIssuedDuringPeriodSharesStockSplits" use="optional" order="3.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/StatementOfIncome">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:title="NetIncomeLossAvailableToCommonStockholdersBasic" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromContinuingOperations" xlink:label="IncomeLossFromContinuingOperations" xlink:title="IncomeLossFromContinuingOperations" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="IncomeLossFromContinuingOperations" xlink:title="calculation: NetIncomeLossAvailableToCommonStockholdersBasic to IncomeLossFromContinuingOperations" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:label="IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:title="IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromContinuingOperations" xlink:to="IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:title="calculation: IncomeLossFromContinuingOperations to IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="OperatingIncomeLoss" xlink:title="OperatingIncomeLoss" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="OperatingIncomeLoss" xlink:title="calculation: IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest to OperatingIncomeLoss" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_Revenues" xlink:label="Revenues" xlink:title="Revenues" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingIncomeLoss" xlink:to="Revenues" xlink:title="calculation: OperatingIncomeLoss to Revenues" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SalesRevenueGoodsNet" xlink:label="SalesRevenueGoodsNet" xlink:title="SalesRevenueGoodsNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Revenues" xlink:to="SalesRevenueGoodsNet" xlink:title="calculation: Revenues to SalesRevenueGoodsNet" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherSalesRevenueNet" xlink:label="OtherSalesRevenueNet" xlink:title="OtherSalesRevenueNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="Revenues" xlink:to="OtherSalesRevenueNet" xlink:title="calculation: Revenues to OtherSalesRevenueNet" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CostsAndExpenses" xlink:label="CostsAndExpenses" xlink:title="CostsAndExpenses" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingIncomeLoss" xlink:to="CostsAndExpenses" xlink:title="calculation: OperatingIncomeLoss to CostsAndExpenses" use="optional" order="2.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:label="ResearchAndDevelopmentExpense" xlink:title="ResearchAndDevelopmentExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="CostsAndExpenses" xlink:to="ResearchAndDevelopmentExpense" xlink:title="calculation: CostsAndExpenses to ResearchAndDevelopmentExpense" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="SellingGeneralAndAdministrativeExpense" xlink:title="SellingGeneralAndAdministrativeExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="CostsAndExpenses" xlink:to="SellingGeneralAndAdministrativeExpense" xlink:title="calculation: CostsAndExpenses to SellingGeneralAndAdministrativeExpense" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CostOfGoodsSold" xlink:label="CostOfGoodsSold" xlink:title="CostOfGoodsSold" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="CostsAndExpenses" xlink:to="CostOfGoodsSold" xlink:title="calculation: CostsAndExpenses to CostOfGoodsSold" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="NonoperatingIncomeExpense" xlink:title="NonoperatingIncomeExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:to="NonoperatingIncomeExpense" xlink:title="calculation: IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest to NonoperatingIncomeExpense" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InvestmentIncomeInterest" xlink:label="InvestmentIncomeInterest" xlink:title="InvestmentIncomeInterest" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NonoperatingIncomeExpense" xlink:to="InvestmentIncomeInterest" xlink:title="calculation: NonoperatingIncomeExpense to InvestmentIncomeInterest" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InterestExpense" xlink:label="InterestExpense" xlink:title="InterestExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NonoperatingIncomeExpense" xlink:to="InterestExpense" xlink:title="calculation: NonoperatingIncomeExpense to InterestExpense" use="optional" order="2.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromEquityMethodInvestments" xlink:label="IncomeLossFromEquityMethodInvestments" xlink:title="IncomeLossFromEquityMethodInvestments" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NonoperatingIncomeExpense" xlink:to="IncomeLossFromEquityMethodInvestments" xlink:title="calculation: NonoperatingIncomeExpense to IncomeLossFromEquityMethodInvestments" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="OtherNonoperatingIncomeExpense" xlink:title="OtherNonoperatingIncomeExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NonoperatingIncomeExpense" xlink:to="OtherNonoperatingIncomeExpense" xlink:title="calculation: NonoperatingIncomeExpense to OtherNonoperatingIncomeExpense" use="optional" order="4.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="IncomeTaxExpenseBenefit" xlink:title="IncomeTaxExpenseBenefit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromContinuingOperations" xlink:to="IncomeTaxExpenseBenefit" xlink:title="calculation: IncomeLossFromContinuingOperations to IncomeTaxExpenseBenefit" use="optional" order="2.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity" xlink:label="IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity" xlink:title="IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:to="IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity" xlink:title="calculation: NetIncomeLossAvailableToCommonStockholdersBasic to IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax" xlink:label="DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax" xlink:title="DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity" xlink:to="DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax" xlink:title="calculation: IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity to DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax" xlink:label="DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax" xlink:title="DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity" xlink:to="DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax" xlink:title="calculation: IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity to DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EarningsPerShareBasic" xlink:label="EarningsPerShareBasic" xlink:title="EarningsPerShareBasic" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsPerBasicShare" xlink:label="IncomeLossFromContinuingOperationsPerBasicShare" xlink:title="IncomeLossFromContinuingOperationsPerBasicShare" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="EarningsPerShareBasic" xlink:to="IncomeLossFromContinuingOperationsPerBasicShare" xlink:title="calculation: EarningsPerShareBasic to IncomeLossFromContinuingOperationsPerBasicShare" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare" xlink:label="IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare" xlink:title="IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="EarningsPerShareBasic" xlink:to="IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare" xlink:title="calculation: EarningsPerShareBasic to IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="EarningsPerShareDiluted" xlink:title="EarningsPerShareDiluted" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsPerDilutedShare" xlink:label="IncomeLossFromContinuingOperationsPerDilutedShare" xlink:title="IncomeLossFromContinuingOperationsPerDilutedShare" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="EarningsPerShareDiluted" xlink:to="IncomeLossFromContinuingOperationsPerDilutedShare" xlink:title="calculation: EarningsPerShareDiluted to IncomeLossFromContinuingOperationsPerDilutedShare" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare" xlink:label="IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare" xlink:title="IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="EarningsPerShareDiluted" xlink:to="IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare" xlink:title="calculation: EarningsPerShareDiluted to IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare" use="optional" order="2.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/CashFlows">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:label="CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:title="CashAndCashEquivalentsPeriodIncreaseDecrease" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="NetCashProvidedByUsedInOperatingActivities" xlink:title="NetCashProvidedByUsedInOperatingActivities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:to="NetCashProvidedByUsedInOperatingActivities" xlink:title="calculation: CashAndCashEquivalentsPeriodIncreaseDecrease to NetCashProvidedByUsedInOperatingActivities" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:title="NetIncomeLossAvailableToCommonStockholdersBasic" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to NetIncomeLossAvailableToCommonStockholdersBasic" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:label="DepreciationDepletionAndAmortization" xlink:title="DepreciationDepletionAndAmortization" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="DepreciationDepletionAndAmortization" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to DepreciationDepletionAndAmortization" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_ProvisionForDoubtfulAccountsAndInventoryWritedown" xlink:label="ProvisionForDoubtfulAccountsAndInventoryWritedown" xlink:title="ProvisionForDoubtfulAccountsAndInventoryWritedown" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="ProvisionForDoubtfulAccountsAndInventoryWritedown" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to ProvisionForDoubtfulAccountsAndInventoryWritedown" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="ShareBasedCompensation" xlink:title="ShareBasedCompensation" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="ShareBasedCompensation" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to ShareBasedCompensation" use="optional" order="4.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AmortizationOfFinancingCostsAndDiscounts" xlink:label="AmortizationOfFinancingCostsAndDiscounts" xlink:title="AmortizationOfFinancingCostsAndDiscounts" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="AmortizationOfFinancingCostsAndDiscounts" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to AmortizationOfFinancingCostsAndDiscounts" use="optional" order="7.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments" xlink:label="AccretionAmortizationOfDiscountsAndPremiumsInvestments" xlink:title="AccretionAmortizationOfDiscountsAndPremiumsInvestments" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="AccretionAmortizationOfDiscountsAndPremiumsInvestments" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to AccretionAmortizationOfDiscountsAndPremiumsInvestments" use="optional" order="9.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ExcessTaxBenefitFromShareBasedCompensationOperatingActivities" xlink:label="ExcessTaxBenefitFromShareBasedCompensationOperatingActivities" xlink:title="ExcessTaxBenefitFromShareBasedCompensationOperatingActivities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="ExcessTaxBenefitFromShareBasedCompensationOperatingActivities" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to ExcessTaxBenefitFromShareBasedCompensationOperatingActivities" use="optional" order="11.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable" xlink:label="IncreaseDecreaseInAccountsReceivable" xlink:title="IncreaseDecreaseInAccountsReceivable" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInAccountsReceivable" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInAccountsReceivable" use="optional" order="12.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInInventories" xlink:label="IncreaseDecreaseInInventories" xlink:title="IncreaseDecreaseInInventories" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInInventories" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInInventories" use="optional" order="13.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidExpense" xlink:label="IncreaseDecreaseInPrepaidExpense" xlink:title="IncreaseDecreaseInPrepaidExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInPrepaidExpense" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInPrepaidExpense" use="optional" order="14.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:label="IncreaseDecreaseInOtherOperatingAssets" xlink:title="IncreaseDecreaseInOtherOperatingAssets" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInOtherOperatingAssets" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInOtherOperatingAssets" use="optional" order="15.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:label="IncreaseDecreaseInAccountsPayable" xlink:title="IncreaseDecreaseInAccountsPayable" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInAccountsPayable" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInAccountsPayable" use="optional" order="16.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:label="IncreaseDecreaseInAccruedLiabilities" xlink:title="IncreaseDecreaseInAccruedLiabilities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInAccruedLiabilities" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInAccruedLiabilities" use="optional" order="17.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:label="IncreaseDecreaseInOtherOperatingLiabilities" xlink:title="IncreaseDecreaseInOtherOperatingLiabilities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="IncreaseDecreaseInOtherOperatingLiabilities" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to IncreaseDecreaseInOtherOperatingLiabilities" use="optional" order="18.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AssetImpairmentCharges" xlink:label="AssetImpairmentCharges" xlink:title="AssetImpairmentCharges" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="AssetImpairmentCharges" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to AssetImpairmentCharges" use="optional" order="5.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_LicenseCostsIncurredButNotPaid" xlink:label="LicenseCostsIncurredButNotPaid" xlink:title="LicenseCostsIncurredButNotPaid" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="LicenseCostsIncurredButNotPaid" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to LicenseCostsIncurredButNotPaid" use="optional" order="6.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherNoncashIncomeExpense" xlink:label="OtherNoncashIncomeExpense" xlink:title="OtherNoncashIncomeExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="OtherNoncashIncomeExpense" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to OtherNoncashIncomeExpense" use="optional" order="10.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_IncomeTaxCashFlows" xlink:label="IncomeTaxCashFlows" xlink:title="IncomeTaxCashFlows" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInOperatingActivities" xlink:to="IncomeTaxCashFlows" xlink:title="calculation: NetCashProvidedByUsedInOperatingActivities to IncomeTaxCashFlows" use="optional" order="8.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="NetCashProvidedByUsedInInvestingActivities" xlink:title="NetCashProvidedByUsedInInvestingActivities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:to="NetCashProvidedByUsedInInvestingActivities" xlink:title="calculation: CashAndCashEquivalentsPeriodIncreaseDecrease to NetCashProvidedByUsedInInvestingActivities" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:label="PaymentsToAcquirePropertyPlantAndEquipment" xlink:title="PaymentsToAcquirePropertyPlantAndEquipment" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivities" xlink:to="PaymentsToAcquirePropertyPlantAndEquipment" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivities to PaymentsToAcquirePropertyPlantAndEquipment" use="optional" order="1.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PaymentsToAcquireHeldToMaturitySecurities" xlink:label="PaymentsToAcquireHeldToMaturitySecurities" xlink:title="PaymentsToAcquireHeldToMaturitySecurities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivities" xlink:to="PaymentsToAcquireHeldToMaturitySecurities" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivities to PaymentsToAcquireHeldToMaturitySecurities" use="optional" order="2.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities" xlink:label="ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities" xlink:title="ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivities" xlink:to="ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivities to ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross" xlink:label="PaymentsToAcquireBusinessesGross" xlink:title="PaymentsToAcquireBusinessesGross" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivities" xlink:to="PaymentsToAcquireBusinessesGross" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivities to PaymentsToAcquireBusinessesGross" use="optional" order="5.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncreaseDecreaseInRestrictedCash" xlink:label="IncreaseDecreaseInRestrictedCash" xlink:title="IncreaseDecreaseInRestrictedCash" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivities" xlink:to="IncreaseDecreaseInRestrictedCash" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivities to IncreaseDecreaseInRestrictedCash" use="optional" order="6.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProceedsFromSaleOfTradingSecuritiesHeldforinvestment" xlink:label="ProceedsFromSaleOfTradingSecuritiesHeldforinvestment" xlink:title="ProceedsFromSaleOfTradingSecuritiesHeldforinvestment" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInInvestingActivities" xlink:to="ProceedsFromSaleOfTradingSecuritiesHeldforinvestment" xlink:title="calculation: NetCashProvidedByUsedInInvestingActivities to ProceedsFromSaleOfTradingSecuritiesHeldforinvestment" order="4.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EffectOfExchangeRateOnCashAndCashEquivalents" xlink:label="EffectOfExchangeRateOnCashAndCashEquivalents" xlink:title="EffectOfExchangeRateOnCashAndCashEquivalents" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:to="EffectOfExchangeRateOnCashAndCashEquivalents" xlink:title="calculation: CashAndCashEquivalentsPeriodIncreaseDecrease to EffectOfExchangeRateOnCashAndCashEquivalents" use="optional" order="4.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="NetCashProvidedByUsedInFinancingActivities" xlink:title="NetCashProvidedByUsedInFinancingActivities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:to="NetCashProvidedByUsedInFinancingActivities" xlink:title="calculation: CashAndCashEquivalentsPeriodIncreaseDecrease to NetCashProvidedByUsedInFinancingActivities" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProceedsFromIssuanceOfSecuredDebt" xlink:label="ProceedsFromIssuanceOfSecuredDebt" xlink:title="ProceedsFromIssuanceOfSecuredDebt" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivities" xlink:to="ProceedsFromIssuanceOfSecuredDebt" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivities to ProceedsFromIssuanceOfSecuredDebt" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PaymentsOfFinancingCosts" xlink:label="PaymentsOfFinancingCosts" xlink:title="PaymentsOfFinancingCosts" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivities" xlink:to="PaymentsOfFinancingCosts" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivities to PaymentsOfFinancingCosts" use="optional" order="3.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RepaymentsOfLongTermCapitalLeaseObligations" xlink:label="RepaymentsOfLongTermCapitalLeaseObligations" xlink:title="RepaymentsOfLongTermCapitalLeaseObligations" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivities" xlink:to="RepaymentsOfLongTermCapitalLeaseObligations" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivities to RepaymentsOfLongTermCapitalLeaseObligations" use="optional" order="5.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="ProceedsFromStockOptionsExercised" xlink:title="ProceedsFromStockOptionsExercised" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivities" xlink:to="ProceedsFromStockOptionsExercised" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivities to ProceedsFromStockOptionsExercised" use="optional" order="7.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" xlink:label="ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" xlink:title="ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivities" xlink:to="ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivities to ExcessTaxBenefitFromShareBasedCompensationFinancingActivities" use="optional" order="8.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_RepaymentsOfConvertibleDebt" xlink:label="RepaymentsOfConvertibleDebt" xlink:title="RepaymentsOfConvertibleDebt" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivities" xlink:to="RepaymentsOfConvertibleDebt" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivities to RepaymentsOfConvertibleDebt" use="optional" order="1.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_PaymentsOfConvertibleDebtHedgeAndWarrantsNet" xlink:label="PaymentsOfConvertibleDebtHedgeAndWarrantsNet" xlink:title="PaymentsOfConvertibleDebtHedgeAndWarrantsNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivities" xlink:to="PaymentsOfConvertibleDebtHedgeAndWarrantsNet" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivities to PaymentsOfConvertibleDebtHedgeAndWarrantsNet" use="optional" order="4.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_PaymentForAcceleratedShareRepurchaseTransactionCost" xlink:label="PaymentForAcceleratedShareRepurchaseTransactionCost" xlink:title="PaymentForAcceleratedShareRepurchaseTransactionCost" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NetCashProvidedByUsedInFinancingActivities" xlink:to="PaymentForAcceleratedShareRepurchaseTransactionCost" xlink:title="calculation: NetCashProvidedByUsedInFinancingActivities to PaymentForAcceleratedShareRepurchaseTransactionCost" order="6.0" weight="-1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureGoodwillAndOtherIntangibleAssetsDetails">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="FiniteLivedIntangibleAssetsNet" xlink:title="FiniteLivedIntangibleAssetsNet" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="FiniteLivedIntangibleAssetsGross" xlink:title="FiniteLivedIntangibleAssetsGross" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsNet" xlink:to="FiniteLivedIntangibleAssetsGross" xlink:title="calculation: FiniteLivedIntangibleAssetsNet to FiniteLivedIntangibleAssetsGross" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:title="FiniteLivedIntangibleAssetsAccumulatedAmortization" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsNet" xlink:to="FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:title="calculation: FiniteLivedIntangibleAssetsNet to FiniteLivedIntangibleAssetsAccumulatedAmortization" use="optional" order="2.0" weight="-1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureMarketableInvestmentsDetails">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldToMaturitySecuritiesFairValue" xlink:label="HeldToMaturitySecuritiesFairValue" xlink:title="HeldToMaturitySecuritiesFairValue" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldtomaturitySecuritiesUnrecognizedHoldingGain" xlink:label="HeldtomaturitySecuritiesUnrecognizedHoldingGain" xlink:title="HeldtomaturitySecuritiesUnrecognizedHoldingGain" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="HeldToMaturitySecuritiesFairValue" xlink:to="HeldtomaturitySecuritiesUnrecognizedHoldingGain" xlink:title="calculation: HeldToMaturitySecuritiesFairValue to HeldtomaturitySecuritiesUnrecognizedHoldingGain" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldToMaturitySecuritiesUnrecognizedHoldingLoss" xlink:label="HeldToMaturitySecuritiesUnrecognizedHoldingLoss" xlink:title="HeldToMaturitySecuritiesUnrecognizedHoldingLoss" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="HeldToMaturitySecuritiesFairValue" xlink:to="HeldToMaturitySecuritiesUnrecognizedHoldingLoss" xlink:title="calculation: HeldToMaturitySecuritiesFairValue to HeldToMaturitySecuritiesUnrecognizedHoldingLoss" use="optional" order="2.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldToMaturitySecurities" xlink:label="HeldToMaturitySecurities" xlink:title="HeldToMaturitySecurities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="HeldToMaturitySecuritiesFairValue" xlink:to="HeldToMaturitySecurities" xlink:title="calculation: HeldToMaturitySecuritiesFairValue to HeldToMaturitySecurities" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldToMaturitySecuritiesCurrent" xlink:label="HeldToMaturitySecuritiesCurrent" xlink:title="HeldToMaturitySecuritiesCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="HeldToMaturitySecurities" xlink:to="HeldToMaturitySecuritiesCurrent" xlink:title="calculation: HeldToMaturitySecurities to HeldToMaturitySecuritiesCurrent" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldToMaturitySecuritiesNoncurrent" xlink:label="HeldToMaturitySecuritiesNoncurrent" xlink:title="HeldToMaturitySecuritiesNoncurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="HeldToMaturitySecurities" xlink:to="HeldToMaturitySecuritiesNoncurrent" xlink:title="calculation: HeldToMaturitySecurities to HeldToMaturitySecuritiesNoncurrent" use="optional" order="2.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureMarketableInvestmentsDetails3">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue" xlink:label="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue" xlink:title="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue" xlink:label="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue" xlink:title="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue" xlink:to="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue" xlink:title="calculation: HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue to HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue" xlink:label="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue" xlink:title="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue" xlink:to="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue" xlink:title="calculation: HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue to HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLosses" xlink:label="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLosses" xlink:title="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLosses" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses" xlink:label="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses" xlink:title="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLosses" xlink:to="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses" xlink:title="calculation: HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLosses to HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses" xlink:label="HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses" xlink:title="HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLosses" xlink:to="HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses" xlink:title="calculation: HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLosses to HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses" use="optional" order="2.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureShareTrackingAwardsPlanDetails2">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax" xlink:label="AllocatedShareBasedCompensationExpenseNetOfTax" xlink:title="AllocatedShareBasedCompensationExpenseNetOfTax" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="AllocatedShareBasedCompensationExpense" xlink:title="AllocatedShareBasedCompensationExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AllocatedShareBasedCompensationExpenseNetOfTax" xlink:to="AllocatedShareBasedCompensationExpense" xlink:title="calculation: AllocatedShareBasedCompensationExpenseNetOfTax to AllocatedShareBasedCompensationExpense" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:label="EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:title="EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AllocatedShareBasedCompensationExpenseNetOfTax" xlink:to="EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:title="calculation: AllocatedShareBasedCompensationExpenseNetOfTax to EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" order="2.0" weight="-1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureDebtDetails">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DebtInstrumentConvertibleInterestExpense" xlink:label="DebtInstrumentConvertibleInterestExpense" xlink:title="DebtInstrumentConvertibleInterestExpense" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InterestExpenseDebtExcludingAmortization" xlink:label="InterestExpenseDebtExcludingAmortization" xlink:title="InterestExpenseDebtExcludingAmortization" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DebtInstrumentConvertibleInterestExpense" xlink:to="InterestExpenseDebtExcludingAmortization" xlink:title="calculation: DebtInstrumentConvertibleInterestExpense to InterestExpenseDebtExcludingAmortization" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AmortizationOfDebtDiscountPremium" xlink:label="AmortizationOfDebtDiscountPremium" xlink:title="AmortizationOfDebtDiscountPremium" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DebtInstrumentConvertibleInterestExpense" xlink:to="AmortizationOfDebtDiscountPremium" xlink:title="calculation: DebtInstrumentConvertibleInterestExpense to AmortizationOfDebtDiscountPremium" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LongTermDebt" xlink:label="LongTermDebt" xlink:title="LongTermDebt" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:label="DebtInstrumentCarryingAmount" xlink:title="DebtInstrumentCarryingAmount" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LongTermDebt" xlink:to="DebtInstrumentCarryingAmount" xlink:title="calculation: LongTermDebt to DebtInstrumentCarryingAmount" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscount" xlink:label="DebtInstrumentUnamortizedDiscount" xlink:title="DebtInstrumentUnamortizedDiscount" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LongTermDebt" xlink:to="DebtInstrumentUnamortizedDiscount" xlink:title="calculation: LongTermDebt to DebtInstrumentUnamortizedDiscount" use="optional" order="2.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InterestExpenseDebt" xlink:label="InterestExpenseDebt" xlink:title="InterestExpenseDebt" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InterestCostsCapitalized" xlink:label="InterestCostsCapitalized" xlink:title="InterestCostsCapitalized" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="InterestExpenseDebt" xlink:to="InterestCostsCapitalized" xlink:title="calculation: InterestExpenseDebt to InterestCostsCapitalized" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InterestExpense" xlink:label="InterestExpense" xlink:title="InterestExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="InterestExpenseDebt" xlink:to="InterestExpense" xlink:title="calculation: InterestExpenseDebt to InterestExpense" use="optional" order="2.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureSaleOfBusinessDetails">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:label="AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:title="AssetsOfDisposalGroupIncludingDiscontinuedOperation" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents" xlink:label="DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents" xlink:title="DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:to="DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents" xlink:title="calculation: AssetsOfDisposalGroupIncludingDiscontinuedOperation to DisposalGroupIncludingDiscontinuedOperationCashAndCashEquivalents" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_DisposalGroupIncludingDiscontinuedOperationAccountsReceivableAndInventory" xlink:label="DisposalGroupIncludingDiscontinuedOperationAccountsReceivableAndInventory" xlink:title="DisposalGroupIncludingDiscontinuedOperationAccountsReceivableAndInventory" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:to="DisposalGroupIncludingDiscontinuedOperationAccountsReceivableAndInventory" xlink:title="calculation: AssetsOfDisposalGroupIncludingDiscontinuedOperation to DisposalGroupIncludingDiscontinuedOperationAccountsReceivableAndInventory" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationDeferredTaxAssets" xlink:label="DisposalGroupIncludingDiscontinuedOperationDeferredTaxAssets" xlink:title="DisposalGroupIncludingDiscontinuedOperationDeferredTaxAssets" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:to="DisposalGroupIncludingDiscontinuedOperationDeferredTaxAssets" xlink:title="calculation: AssetsOfDisposalGroupIncludingDiscontinuedOperation to DisposalGroupIncludingDiscontinuedOperationDeferredTaxAssets" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherAssets" xlink:label="DisposalGroupIncludingDiscontinuedOperationOtherAssets" xlink:title="DisposalGroupIncludingDiscontinuedOperationOtherAssets" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:to="DisposalGroupIncludingDiscontinuedOperationOtherAssets" xlink:title="calculation: AssetsOfDisposalGroupIncludingDiscontinuedOperation to DisposalGroupIncludingDiscontinuedOperationOtherAssets" use="optional" order="4.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureAccruedExpensesDetails">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="AccruedLiabilitiesCurrent" xlink:title="AccruedLiabilitiesCurrent" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_AccruedRoyaltiesAndRebatesCurrent" xlink:label="AccruedRoyaltiesAndRebatesCurrent" xlink:title="AccruedRoyaltiesAndRebatesCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AccruedLiabilitiesCurrent" xlink:to="AccruedRoyaltiesAndRebatesCurrent" xlink:title="calculation: AccruedLiabilitiesCurrent to AccruedRoyaltiesAndRebatesCurrent" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:label="EmployeeRelatedLiabilitiesCurrent" xlink:title="EmployeeRelatedLiabilitiesCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AccruedLiabilitiesCurrent" xlink:to="EmployeeRelatedLiabilitiesCurrent" xlink:title="calculation: AccruedLiabilitiesCurrent to EmployeeRelatedLiabilitiesCurrent" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_AccruedResearchRelatedCostsCurrent" xlink:label="AccruedResearchRelatedCostsCurrent" xlink:title="AccruedResearchRelatedCostsCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AccruedLiabilitiesCurrent" xlink:to="AccruedResearchRelatedCostsCurrent" xlink:title="calculation: AccruedLiabilitiesCurrent to AccruedResearchRelatedCostsCurrent" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherAccruedLiabilitiesCurrent" xlink:label="OtherAccruedLiabilitiesCurrent" xlink:title="OtherAccruedLiabilitiesCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="AccruedLiabilitiesCurrent" xlink:to="OtherAccruedLiabilitiesCurrent" xlink:title="calculation: AccruedLiabilitiesCurrent to OtherAccruedLiabilitiesCurrent" use="optional" order="4.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureIncomeTaxesDetails">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="IncomeTaxExpenseBenefit" xlink:title="IncomeTaxExpenseBenefit" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit" xlink:label="DeferredIncomeTaxExpenseBenefit" xlink:title="DeferredIncomeTaxExpenseBenefit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="DeferredIncomeTaxExpenseBenefit" xlink:title="calculation: IncomeTaxExpenseBenefit to DeferredIncomeTaxExpenseBenefit" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:label="DeferredForeignIncomeTaxExpenseBenefit" xlink:title="DeferredForeignIncomeTaxExpenseBenefit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredIncomeTaxExpenseBenefit" xlink:to="DeferredForeignIncomeTaxExpenseBenefit" xlink:title="calculation: DeferredIncomeTaxExpenseBenefit to DeferredForeignIncomeTaxExpenseBenefit" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:label="DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:title="DeferredStateAndLocalIncomeTaxExpenseBenefit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredIncomeTaxExpenseBenefit" xlink:to="DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:title="calculation: DeferredIncomeTaxExpenseBenefit to DeferredStateAndLocalIncomeTaxExpenseBenefit" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:label="DeferredFederalIncomeTaxExpenseBenefit" xlink:title="DeferredFederalIncomeTaxExpenseBenefit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredIncomeTaxExpenseBenefit" xlink:to="DeferredFederalIncomeTaxExpenseBenefit" xlink:title="calculation: DeferredIncomeTaxExpenseBenefit to DeferredFederalIncomeTaxExpenseBenefit" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_NoncurrentIncomeTaxExpenseBenefit" xlink:label="NoncurrentIncomeTaxExpenseBenefit" xlink:title="NoncurrentIncomeTaxExpenseBenefit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="NoncurrentIncomeTaxExpenseBenefit" xlink:title="calculation: IncomeTaxExpenseBenefit to NoncurrentIncomeTaxExpenseBenefit" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_NoncurrentForeignTaxExpenseBenefit" xlink:label="NoncurrentForeignTaxExpenseBenefit" xlink:title="NoncurrentForeignTaxExpenseBenefit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NoncurrentIncomeTaxExpenseBenefit" xlink:to="NoncurrentForeignTaxExpenseBenefit" xlink:title="calculation: NoncurrentIncomeTaxExpenseBenefit to NoncurrentForeignTaxExpenseBenefit" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_NoncurrentStateAndLocalTaxExpenseBenefit" xlink:label="NoncurrentStateAndLocalTaxExpenseBenefit" xlink:title="NoncurrentStateAndLocalTaxExpenseBenefit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NoncurrentIncomeTaxExpenseBenefit" xlink:to="NoncurrentStateAndLocalTaxExpenseBenefit" xlink:title="calculation: NoncurrentIncomeTaxExpenseBenefit to NoncurrentStateAndLocalTaxExpenseBenefit" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_NoncurrentFederalTaxExpenseBenefit" xlink:label="NoncurrentFederalTaxExpenseBenefit" xlink:title="NoncurrentFederalTaxExpenseBenefit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="NoncurrentIncomeTaxExpenseBenefit" xlink:to="NoncurrentFederalTaxExpenseBenefit" xlink:title="calculation: NoncurrentIncomeTaxExpenseBenefit to NoncurrentFederalTaxExpenseBenefit" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CurrentIncomeTaxExpenseBenefit" xlink:label="CurrentIncomeTaxExpenseBenefit" xlink:title="CurrentIncomeTaxExpenseBenefit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="CurrentIncomeTaxExpenseBenefit" xlink:title="calculation: IncomeTaxExpenseBenefit to CurrentIncomeTaxExpenseBenefit" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CurrentForeignTaxExpenseBenefit" xlink:label="CurrentForeignTaxExpenseBenefit" xlink:title="CurrentForeignTaxExpenseBenefit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="CurrentIncomeTaxExpenseBenefit" xlink:to="CurrentForeignTaxExpenseBenefit" xlink:title="calculation: CurrentIncomeTaxExpenseBenefit to CurrentForeignTaxExpenseBenefit" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:label="CurrentStateAndLocalTaxExpenseBenefit" xlink:title="CurrentStateAndLocalTaxExpenseBenefit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="CurrentIncomeTaxExpenseBenefit" xlink:to="CurrentStateAndLocalTaxExpenseBenefit" xlink:title="calculation: CurrentIncomeTaxExpenseBenefit to CurrentStateAndLocalTaxExpenseBenefit" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CurrentFederalTaxExpenseBenefit" xlink:label="CurrentFederalTaxExpenseBenefit" xlink:title="CurrentFederalTaxExpenseBenefit" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="CurrentIncomeTaxExpenseBenefit" xlink:to="CurrentFederalTaxExpenseBenefit" xlink:title="calculation: CurrentIncomeTaxExpenseBenefit to CurrentFederalTaxExpenseBenefit" use="optional" order="1.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureIncomeTaxesDetails2">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="IncomeTaxExpenseBenefit" xlink:title="IncomeTaxExpenseBenefit" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:label="IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:title="IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" xlink:title="calculation: IncomeTaxExpenseBenefit to IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:label="IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:title="IncomeTaxReconciliationStateAndLocalIncomeTaxes" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="IncomeTaxReconciliationStateAndLocalIncomeTaxes" xlink:title="calculation: IncomeTaxExpenseBenefit to IncomeTaxReconciliationStateAndLocalIncomeTaxes" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:label="IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:title="IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" xlink:title="calculation: IncomeTaxExpenseBenefit to IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeTaxReconciliationTaxCredits" xlink:label="IncomeTaxReconciliationTaxCredits" xlink:title="IncomeTaxReconciliationTaxCredits" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="IncomeTaxReconciliationTaxCredits" xlink:title="calculation: IncomeTaxExpenseBenefit to IncomeTaxReconciliationTaxCredits" use="optional" order="4.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_IncomeTaxReconciliationIncentiveStockOptionExpense" xlink:label="IncomeTaxReconciliationIncentiveStockOptionExpense" xlink:title="IncomeTaxReconciliationIncentiveStockOptionExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="IncomeTaxReconciliationIncentiveStockOptionExpense" xlink:title="calculation: IncomeTaxExpenseBenefit to IncomeTaxReconciliationIncentiveStockOptionExpense" use="optional" order="5.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeTaxReconciliationDeductions" xlink:label="IncomeTaxReconciliationDeductions" xlink:title="IncomeTaxReconciliationDeductions" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="IncomeTaxReconciliationDeductions" xlink:title="calculation: IncomeTaxExpenseBenefit to IncomeTaxReconciliationDeductions" use="optional" order="6.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:label="IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:title="IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost" xlink:title="calculation: IncomeTaxExpenseBenefit to IncomeTaxReconciliationNondeductibleExpenseShareBasedCompensationCost" use="optional" order="7.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpense" xlink:label="IncomeTaxReconciliationNondeductibleExpense" xlink:title="IncomeTaxReconciliationNondeductibleExpense" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="IncomeTaxExpenseBenefit" xlink:to="IncomeTaxReconciliationNondeductibleExpense" xlink:title="calculation: IncomeTaxExpenseBenefit to IncomeTaxReconciliationNondeductibleExpense" use="optional" order="8.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureIncomeTaxesDetails3">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxAssetsNet" xlink:label="DeferredTaxAssetsNet" xlink:title="DeferredTaxAssetsNet" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_DeferredTaxAssetsNetBeforeValuationAllowance" xlink:label="DeferredTaxAssetsNetBeforeValuationAllowance" xlink:title="DeferredTaxAssetsNetBeforeValuationAllowance" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsNet" xlink:to="DeferredTaxAssetsNetBeforeValuationAllowance" xlink:title="calculation: DeferredTaxAssetsNet to DeferredTaxAssetsNetBeforeValuationAllowance" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxLiabilitiesOther" xlink:label="DeferredTaxLiabilitiesOther" xlink:title="DeferredTaxLiabilitiesOther" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsNetBeforeValuationAllowance" xlink:to="DeferredTaxLiabilitiesOther" xlink:title="calculation: DeferredTaxAssetsNetBeforeValuationAllowance to DeferredTaxLiabilitiesOther" use="optional" order="2.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:label="DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:title="DeferredTaxLiabilitiesPropertyPlantAndEquipment" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsNetBeforeValuationAllowance" xlink:to="DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:title="calculation: DeferredTaxAssetsNetBeforeValuationAllowance to DeferredTaxLiabilitiesPropertyPlantAndEquipment" use="optional" order="1.0" weight="-1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxAssetsGross" xlink:label="DeferredTaxAssetsGross" xlink:title="DeferredTaxAssetsGross" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsNetBeforeValuationAllowance" xlink:to="DeferredTaxAssetsGross" xlink:title="calculation: DeferredTaxAssetsNetBeforeValuationAllowance to DeferredTaxAssetsGross" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsGeneralBusiness" xlink:label="DeferredTaxAssetsTaxCreditCarryforwardsGeneralBusiness" xlink:title="DeferredTaxAssetsTaxCreditCarryforwardsGeneralBusiness" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxAssetsTaxCreditCarryforwardsGeneralBusiness" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxAssetsTaxCreditCarryforwardsGeneralBusiness" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsImpairmentLosses" xlink:label="DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsImpairmentLosses" xlink:title="DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsImpairmentLosses" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsImpairmentLosses" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsImpairmentLosses" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxAssetsUnrealizedLossesOnTradingSecurities" xlink:label="DeferredTaxAssetsUnrealizedLossesOnTradingSecurities" xlink:title="DeferredTaxAssetsUnrealizedLossesOnTradingSecurities" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxAssetsUnrealizedLossesOnTradingSecurities" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxAssetsUnrealizedLossesOnTradingSecurities" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_DeferredTaxAssetsCapitalizedLicenseFees" xlink:label="DeferredTaxAssetsCapitalizedLicenseFees" xlink:title="DeferredTaxAssetsCapitalizedLicenseFees" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxAssetsCapitalizedLicenseFees" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxAssetsCapitalizedLicenseFees" use="optional" order="4.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_DeferredTaxAssetsNonqualifiedStockOptions" xlink:label="DeferredTaxAssetsNonqualifiedStockOptions" xlink:title="DeferredTaxAssetsNonqualifiedStockOptions" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxAssetsNonqualifiedStockOptions" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxAssetsNonqualifiedStockOptions" use="optional" order="5.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_DeferredTaxAssetsSupplementalExecutiveRetirementPlan" xlink:label="DeferredTaxAssetsSupplementalExecutiveRetirementPlan" xlink:title="DeferredTaxAssetsSupplementalExecutiveRetirementPlan" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxAssetsSupplementalExecutiveRetirementPlan" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxAssetsSupplementalExecutiveRetirementPlan" use="optional" order="6.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_DeferredTaxAssetsShareTrackingAwardsPlan" xlink:label="DeferredTaxAssetsShareTrackingAwardsPlan" xlink:title="DeferredTaxAssetsShareTrackingAwardsPlan" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxAssetsShareTrackingAwardsPlan" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxAssetsShareTrackingAwardsPlan" use="optional" order="7.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxAssetsOther" xlink:label="DeferredTaxAssetsOther" xlink:title="DeferredTaxAssetsOther" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsGross" xlink:to="DeferredTaxAssetsOther" xlink:title="calculation: DeferredTaxAssetsGross to DeferredTaxAssetsOther" use="optional" order="8.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="DeferredTaxAssetsValuationAllowance" xlink:title="DeferredTaxAssetsValuationAllowance" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DeferredTaxAssetsNet" xlink:to="DeferredTaxAssetsValuationAllowance" xlink:title="calculation: DeferredTaxAssetsNet to DeferredTaxAssetsValuationAllowance" use="optional" order="2.0" weight="-1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureDebtDetails3">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LongTermDebt" xlink:label="LongTermDebt" xlink:title="LongTermDebt" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:label="LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:title="LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LongTermDebt" xlink:to="LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:title="calculation: LongTermDebt to LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:label="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:title="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LongTermDebt" xlink:to="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:title="calculation: LongTermDebt to LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:label="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:title="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LongTermDebt" xlink:to="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:title="calculation: LongTermDebt to LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:label="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:title="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LongTermDebt" xlink:to="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:title="calculation: LongTermDebt to LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" use="optional" order="4.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:label="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:title="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="LongTermDebt" xlink:to="LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:title="calculation: LongTermDebt to LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" use="optional" order="5.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InventoryNet" xlink:label="InventoryNet" xlink:title="InventoryNet" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InventoryRawMaterialsNetOfReserves" xlink:label="InventoryRawMaterialsNetOfReserves" xlink:title="InventoryRawMaterialsNetOfReserves" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="InventoryNet" xlink:to="InventoryRawMaterialsNetOfReserves" xlink:title="calculation: InventoryNet to InventoryRawMaterialsNetOfReserves" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InventoryWorkInProcessNetOfReserves" xlink:label="InventoryWorkInProcessNetOfReserves" xlink:title="InventoryWorkInProcessNetOfReserves" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="InventoryNet" xlink:to="InventoryWorkInProcessNetOfReserves" xlink:title="calculation: InventoryNet to InventoryWorkInProcessNetOfReserves" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_InventoryFinishedGoodsNetOfReserves" xlink:label="InventoryFinishedGoodsNetOfReserves" xlink:title="InventoryFinishedGoodsNetOfReserves" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="InventoryNet" xlink:to="InventoryFinishedGoodsNetOfReserves" xlink:title="calculation: InventoryNet to InventoryFinishedGoodsNetOfReserves" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OtherInventoryNetOfReserves" xlink:label="OtherInventoryNetOfReserves" xlink:title="OtherInventoryNetOfReserves" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="InventoryNet" xlink:to="OtherInventoryNetOfReserves" xlink:title="calculation: InventoryNet to OtherInventoryNetOfReserves" use="optional" order="4.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails2">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:label="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:title="FiniteLivedIntangibleAssetsFutureAmortizationExpense" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearOne" xlink:label="FutureAmortizationExpenseYearOne" xlink:title="FutureAmortizationExpenseYearOne" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseYearOne" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseYearOne" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearTwo" xlink:label="FutureAmortizationExpenseYearTwo" xlink:title="FutureAmortizationExpenseYearTwo" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseYearTwo" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseYearTwo" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearThree" xlink:label="FutureAmortizationExpenseYearThree" xlink:title="FutureAmortizationExpenseYearThree" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseYearThree" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseYearThree" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearFour" xlink:label="FutureAmortizationExpenseYearFour" xlink:title="FutureAmortizationExpenseYearFour" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseYearFour" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseYearFour" use="optional" order="4.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseYearFive" xlink:label="FutureAmortizationExpenseYearFive" xlink:title="FutureAmortizationExpenseYearFive" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseYearFive" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseYearFive" use="optional" order="5.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_FutureAmortizationExpenseAfterYearFive" xlink:label="FutureAmortizationExpenseAfterYearFive" xlink:title="FutureAmortizationExpenseAfterYearFive" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FiniteLivedIntangibleAssetsFutureAmortizationExpense" xlink:to="FutureAmortizationExpenseAfterYearFive" xlink:title="calculation: FiniteLivedIntangibleAssetsFutureAmortizationExpense to FutureAmortizationExpenseAfterYearFive" use="optional" order="6.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails3">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="PropertyPlantAndEquipmentNet" xlink:title="PropertyPlantAndEquipmentNet" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="PropertyPlantAndEquipmentGross" xlink:title="PropertyPlantAndEquipmentGross" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="PropertyPlantAndEquipmentNet" xlink:to="PropertyPlantAndEquipmentGross" xlink:title="calculation: PropertyPlantAndEquipmentNet to PropertyPlantAndEquipmentGross" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:title="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="PropertyPlantAndEquipmentNet" xlink:to="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:title="calculation: PropertyPlantAndEquipmentNet to AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" use="optional" order="2.0" weight="-1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureCommitmentsAndContingenciesDetails">
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_FutureMilestonePaymentsDue" xlink:label="FutureMilestonePaymentsDue" xlink:title="FutureMilestonePaymentsDue" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_FutureMilestonePaymentsDueCurrent" xlink:label="FutureMilestonePaymentsDueCurrent" xlink:title="FutureMilestonePaymentsDueCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FutureMilestonePaymentsDue" xlink:to="FutureMilestonePaymentsDueCurrent" xlink:title="calculation: FutureMilestonePaymentsDue to FutureMilestonePaymentsDueCurrent" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_FutureMilestonePaymentsDueInTwoYears" xlink:label="FutureMilestonePaymentsDueInTwoYears" xlink:title="FutureMilestonePaymentsDueInTwoYears" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FutureMilestonePaymentsDue" xlink:to="FutureMilestonePaymentsDueInTwoYears" xlink:title="calculation: FutureMilestonePaymentsDue to FutureMilestonePaymentsDueInTwoYears" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_FutureMilestonePaymentsDueInThreeYears" xlink:label="FutureMilestonePaymentsDueInThreeYears" xlink:title="FutureMilestonePaymentsDueInThreeYears" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FutureMilestonePaymentsDue" xlink:to="FutureMilestonePaymentsDueInThreeYears" xlink:title="calculation: FutureMilestonePaymentsDue to FutureMilestonePaymentsDueInThreeYears" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_FutureMilestonePaymentsDueInFourYears" xlink:label="FutureMilestonePaymentsDueInFourYears" xlink:title="FutureMilestonePaymentsDueInFourYears" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FutureMilestonePaymentsDue" xlink:to="FutureMilestonePaymentsDueInFourYears" xlink:title="calculation: FutureMilestonePaymentsDue to FutureMilestonePaymentsDueInFourYears" use="optional" order="4.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_FutureMilestonePaymentsDueInFiveYears" xlink:label="FutureMilestonePaymentsDueInFiveYears" xlink:title="FutureMilestonePaymentsDueInFiveYears" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FutureMilestonePaymentsDue" xlink:to="FutureMilestonePaymentsDueInFiveYears" xlink:title="calculation: FutureMilestonePaymentsDue to FutureMilestonePaymentsDueInFiveYears" use="optional" order="5.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_FutureMilestonePaymentsDueThereafter" xlink:label="FutureMilestonePaymentsDueThereafter" xlink:title="FutureMilestonePaymentsDueThereafter" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="FutureMilestonePaymentsDue" xlink:to="FutureMilestonePaymentsDueThereafter" xlink:title="calculation: FutureMilestonePaymentsDue to FutureMilestonePaymentsDueThereafter" use="optional" order="6.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:label="OperatingLeasesFutureMinimumPaymentsDue" xlink:title="OperatingLeasesFutureMinimumPaymentsDue" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:label="OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:title="OperatingLeasesFutureMinimumPaymentsDueCurrent" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueCurrent" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:label="OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:title="OperatingLeasesFutureMinimumPaymentsDueInTwoYears" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueInTwoYears" use="optional" order="2.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:label="OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:title="OperatingLeasesFutureMinimumPaymentsDueInThreeYears" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueInThreeYears" use="optional" order="3.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:label="OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:title="OperatingLeasesFutureMinimumPaymentsDueInFourYears" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueInFourYears" use="optional" order="4.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:label="OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:title="OperatingLeasesFutureMinimumPaymentsDueInFiveYears" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueInFiveYears" use="optional" order="5.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:label="OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:title="OperatingLeasesFutureMinimumPaymentsDueThereafter" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="OperatingLeasesFutureMinimumPaymentsDue" xlink:to="OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:title="calculation: OperatingLeasesFutureMinimumPaymentsDue to OperatingLeasesFutureMinimumPaymentsDueThereafter" use="optional" order="6.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureEmployeeBenefitPlansDetails">
    <loc xlink:type="locator" xlink:href="uthr-20111231.xsd#uthr_DefinedBenefitPlanExpectedFutureBenefitPayments" xlink:label="DefinedBenefitPlanExpectedFutureBenefitPayments" xlink:title="DefinedBenefitPlanExpectedFutureBenefitPayments" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsInYearFour" xlink:label="DefinedBenefitPlanExpectedFutureBenefitPaymentsInYearFour" xlink:title="DefinedBenefitPlanExpectedFutureBenefitPaymentsInYearFour" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DefinedBenefitPlanExpectedFutureBenefitPayments" xlink:to="DefinedBenefitPlanExpectedFutureBenefitPaymentsInYearFour" xlink:title="calculation: DefinedBenefitPlanExpectedFutureBenefitPayments to DefinedBenefitPlanExpectedFutureBenefitPaymentsInYearFour" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsInFiveFiscalYearsThereafter" xlink:label="DefinedBenefitPlanExpectedFutureBenefitPaymentsInFiveFiscalYearsThereafter" xlink:title="DefinedBenefitPlanExpectedFutureBenefitPaymentsInFiveFiscalYearsThereafter" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="DefinedBenefitPlanExpectedFutureBenefitPayments" xlink:to="DefinedBenefitPlanExpectedFutureBenefitPaymentsInFiveFiscalYearsThereafter" xlink:title="calculation: DefinedBenefitPlanExpectedFutureBenefitPayments to DefinedBenefitPlanExpectedFutureBenefitPaymentsInFiveFiscalYearsThereafter" use="optional" order="2.0" weight="1.0" />
  </calculationLink>
  <calculationLink xlink:type="extended" xlink:role="http://www.unither.com/role/DisclosureSegmentInformationDetails">
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_GrossProfit" xlink:label="GrossProfit" xlink:title="GrossProfit" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_SalesRevenueGoodsNet" xlink:label="SalesRevenueGoodsNet" xlink:title="SalesRevenueGoodsNet" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="GrossProfit" xlink:to="SalesRevenueGoodsNet" xlink:title="calculation: GrossProfit to SalesRevenueGoodsNet" use="optional" order="1.0" weight="1.0" />
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2011/elts/us-gaap-2011-01-31.xsd#us-gaap_CostOfGoodsSold" xlink:label="CostOfGoodsSold" xlink:title="CostOfGoodsSold" />
    <calculationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/summation-item" xlink:from="GrossProfit" xlink:to="CostOfGoodsSold" xlink:title="calculation: GrossProfit to CostOfGoodsSold" use="optional" order="2.0" weight="-1.0" />
  </calculationLink>
</linkbase>
