<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019d1dc9-bc28-7738-a60c-cb3403f56a4c,g:9ef47c95-ba6b-4823-ba37-566246fe1199-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="https://xbrl.org/2023/arcrole/summation-item" xlink:type="simple" xlink:href="https://www.xbrl.org/2023/calculation-1.1.xsd#summation-item"/>
  <link:roleRef roleURI="http://www.unither.com/role/ConsolidatedBalanceSheets" xlink:type="simple" xlink:href="uthr-20260331.xsd#ConsolidatedBalanceSheets"/>
  <link:calculationLink xlink:role="http://www.unither.com/role/ConsolidatedBalanceSheets" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019d1dc9-bd6a-70ad-aec0-284bc58fa642" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019d1dc9-bd6a-7982-9af2-10e16056933e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019d1dc9-bd6a-70ad-aec0-284bc58fa642" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_019d1dc9-bd6a-7982-9af2-10e16056933e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecuritiesCurrent_019d1dc9-bd6a-791c-8f36-f19a9d9c9f6a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MarketableSecuritiesCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019d1dc9-bd6a-70ad-aec0-284bc58fa642" xlink:to="loc_us-gaap_MarketableSecuritiesCurrent_019d1dc9-bd6a-791c-8f36-f19a9d9c9f6a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_019d1dc9-bd6a-7b80-b9cd-debf847999be" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019d1dc9-bd6a-70ad-aec0-284bc58fa642" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_019d1dc9-bd6a-7b80-b9cd-debf847999be" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_019d1dc9-bd6a-7380-939a-04ac42c07a1d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InventoryNet"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019d1dc9-bd6a-70ad-aec0-284bc58fa642" xlink:to="loc_us-gaap_InventoryNet_019d1dc9-bd6a-7380-939a-04ac42c07a1d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsCurrent_019d1dc9-bd6a-7cc6-a1b7-f31a169a920a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsCurrent"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsCurrent_019d1dc9-bd6a-70ad-aec0-284bc58fa642" xlink:to="loc_us-gaap_OtherAssetsCurrent_019d1dc9-bd6a-7cc6-a1b7-f31a169a920a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019d1dc9-bd6a-7b26-a7c6-990d90308656" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019d1dc9-bd6a-7260-bad1-8ddd844a4f91" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019d1dc9-bd6a-7b26-a7c6-990d90308656" xlink:to="loc_us-gaap_LiabilitiesCurrent_019d1dc9-bd6a-7260-bad1-8ddd844a4f91" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_019d1dc9-bd6a-7593-b475-870549a7ba34" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesNoncurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Liabilities_019d1dc9-bd6a-7b26-a7c6-990d90308656" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_019d1dc9-bd6a-7593-b475-870549a7ba34" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019d1dc9-bd6a-73e6-9502-ab4eb8b691b9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsCurrent_019d1dc9-bd6a-7c4e-aa75-1926c9bac3f7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d1dc9-bd6a-73e6-9502-ab4eb8b691b9" xlink:to="loc_us-gaap_AssetsCurrent_019d1dc9-bd6a-7c4e-aa75-1926c9bac3f7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketableSecuritiesNoncurrent_019d1dc9-bd6a-7641-8d9a-2adfc6c1dacb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MarketableSecuritiesNoncurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d1dc9-bd6a-73e6-9502-ab4eb8b691b9" xlink:to="loc_us-gaap_MarketableSecuritiesNoncurrent_019d1dc9-bd6a-7641-8d9a-2adfc6c1dacb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetIncludingGoodwill_019d1dc9-bd6a-7bd3-82eb-36f901b4c929" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsNetIncludingGoodwill"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d1dc9-bd6a-73e6-9502-ab4eb8b691b9" xlink:to="loc_us-gaap_IntangibleAssetsNetIncludingGoodwill_019d1dc9-bd6a-7bd3-82eb-36f901b4c929" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019d1dc9-bd6a-7b2a-92ef-a90060036889" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d1dc9-bd6a-73e6-9502-ab4eb8b691b9" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_019d1dc9-bd6a-7b2a-92ef-a90060036889" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxAssetsNet_019d1dc9-bd6a-7906-b54a-62d7e93b2449" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxAssetsNet"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d1dc9-bd6a-73e6-9502-ab4eb8b691b9" xlink:to="loc_us-gaap_DeferredIncomeTaxAssetsNet_019d1dc9-bd6a-7906-b54a-62d7e93b2449" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_019d1dc9-bd6a-7ccf-892c-26107e23f4d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_Assets_019d1dc9-bd6a-73e6-9502-ab4eb8b691b9" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_019d1dc9-bd6a-7ccf-892c-26107e23f4d5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019d1dc9-bd6a-7cd1-a73d-77f44aead81b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockValue_019d1dc9-bd6a-7bfb-98a8-72d9424fbc5d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PreferredStockValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019d1dc9-bd6a-7cd1-a73d-77f44aead81b" xlink:to="loc_us-gaap_PreferredStockValue_019d1dc9-bd6a-7bfb-98a8-72d9424fbc5d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_019d1dc9-bd6a-7a76-8aea-8d669f761272" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019d1dc9-bd6a-7cd1-a73d-77f44aead81b" xlink:to="loc_us-gaap_CommonStockValue_019d1dc9-bd6a-7a76-8aea-8d669f761272" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_019d1dc9-bd6a-76a8-8bd9-8af08bc67d90" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019d1dc9-bd6a-7cd1-a73d-77f44aead81b" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_019d1dc9-bd6a-76a8-8bd9-8af08bc67d90" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019d1dc9-bd6a-7ab2-aa24-0ed135c4de95" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019d1dc9-bd6a-7cd1-a73d-77f44aead81b" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_019d1dc9-bd6a-7ab2-aa24-0ed135c4de95" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonValue_019d1dc9-bd6a-76f1-b559-8668c5033491" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonValue"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019d1dc9-bd6a-7cd1-a73d-77f44aead81b" xlink:to="loc_us-gaap_TreasuryStockCommonValue_019d1dc9-bd6a-76f1-b559-8668c5033491" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019d1dc9-bd6a-786d-9bc4-a8099414502a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:calculationArc order="6" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_StockholdersEquity_019d1dc9-bd6a-7cd1-a73d-77f44aead81b" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_019d1dc9-bd6a-786d-9bc4-a8099414502a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrent_019d1dc9-bd6a-7ddd-8c7e-e34948e577ce" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesCurrent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_019d1dc9-bd6a-7adb-a3b0-8564e5150b69" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019d1dc9-bd6a-7ddd-8c7e-e34948e577ce" xlink:to="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_019d1dc9-bd6a-7adb-a3b0-8564e5150b69" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesCurrent_019d1dc9-bd6a-74b0-b2b7-54436b9d2c10" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesCurrent_019d1dc9-bd6a-7ddd-8c7e-e34948e577ce" xlink:to="loc_us-gaap_OtherLiabilitiesCurrent_019d1dc9-bd6a-74b0-b2b7-54436b9d2c10" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_019d1dc9-bd6a-7c35-ba40-4d442ff91266" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_019d1dc9-bd6a-765b-81aa-13079605f245" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Liabilities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019d1dc9-bd6a-7c35-ba40-4d442ff91266" xlink:to="loc_us-gaap_Liabilities_019d1dc9-bd6a-765b-81aa-13079605f245" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019d1dc9-bd6a-73d0-977c-fa6ffccc0b22" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019d1dc9-bd6a-7c35-ba40-4d442ff91266" xlink:to="loc_us-gaap_StockholdersEquity_019d1dc9-bd6a-73d0-977c-fa6ffccc0b22" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommitmentsAndContingencies_019d1dc9-bd6a-7668-a7dd-1369f882ab94" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommitmentsAndContingencies"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquity_019d1dc9-bd6a-7c35-ba40-4d442ff91266" xlink:to="loc_us-gaap_CommitmentsAndContingencies_019d1dc9-bd6a-7668-a7dd-1369f882ab94" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.unither.com/role/ConsolidatedStatementsofOperations" xlink:type="simple" xlink:href="uthr-20260331.xsd#ConsolidatedStatementsofOperations"/>
  <link:calculationLink xlink:role="http://www.unither.com/role/ConsolidatedStatementsofOperations" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019d1dc9-bd6a-74c0-8589-288b9f677681" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019d1dc9-bd6a-710a-9396-fc587c3c2823" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019d1dc9-bd6a-74c0-8589-288b9f677681" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019d1dc9-bd6a-710a-9396-fc587c3c2823" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019d1dc9-bd6a-7f0e-a4b7-24fa1db8e031" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetIncomeLoss_019d1dc9-bd6a-74c0-8589-288b9f677681" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019d1dc9-bd6a-7f0e-a4b7-24fa1db8e031" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_019d1dc9-bd6a-7a12-96ce-5c49d64787ad" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostsAndExpenses"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_019d1dc9-bd6a-7fbd-b40d-833a258484b8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_019d1dc9-bd6a-7a12-96ce-5c49d64787ad" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_019d1dc9-bd6a-7fbd-b40d-833a258484b8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019d1dc9-bd6a-73ec-9342-453dbb4a6f5b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_019d1dc9-bd6a-7a12-96ce-5c49d64787ad" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_019d1dc9-bd6a-73ec-9342-453dbb4a6f5b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_019d1dc9-bd6a-711c-9c15-0df2190b9604" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CostsAndExpenses_019d1dc9-bd6a-7a12-96ce-5c49d64787ad" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_019d1dc9-bd6a-711c-9c15-0df2190b9604" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019d1dc9-bd6a-75be-bc64-4951eb8bd55d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019d1dc9-bd6a-7cfc-92dc-d668712c2285" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019d1dc9-bd6a-75be-bc64-4951eb8bd55d" xlink:to="loc_us-gaap_OperatingIncomeLoss_019d1dc9-bd6a-7cfc-92dc-d668712c2285" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019d1dc9-bd6a-76a8-908e-0ba411f3e30b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019d1dc9-bd6a-75be-bc64-4951eb8bd55d" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_019d1dc9-bd6a-76a8-908e-0ba411f3e30b" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_019d1dc9-bd6a-7c5e-8f3e-c6f5146c8bec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019d1dc9-bd6a-7df4-a56c-1462e903e08c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_019d1dc9-bd6a-7c5e-8f3e-c6f5146c8bec" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019d1dc9-bd6a-7df4-a56c-1462e903e08c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpenses_019d1dc9-bd6a-72f5-be72-4e806e1f43e5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostsAndExpenses"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OperatingIncomeLoss_019d1dc9-bd6a-7c5e-8f3e-c6f5146c8bec" xlink:to="loc_us-gaap_CostsAndExpenses_019d1dc9-bd6a-72f5-be72-4e806e1f43e5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_019d1dc9-bd6a-7eb2-9779-d9ef07dad9d6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeInterest_019d1dc9-bd6a-71ac-b083-70356461d697" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentIncomeInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019d1dc9-bd6a-7eb2-9779-d9ef07dad9d6" xlink:to="loc_us-gaap_InvestmentIncomeInterest_019d1dc9-bd6a-71ac-b083-70356461d697" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019d1dc9-bd6a-7428-8a96-5098b6b43ab9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019d1dc9-bd6a-7eb2-9779-d9ef07dad9d6" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019d1dc9-bd6a-7428-8a96-5098b6b43ab9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_019d1dc9-bd6a-7538-86a9-f0700308999b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NonoperatingIncomeExpense_019d1dc9-bd6a-7eb2-9779-d9ef07dad9d6" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_019d1dc9-bd6a-7538-86a9-f0700308999b" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.unither.com/role/ConsolidatedStatementsofComprehensiveIncome" xlink:type="simple" xlink:href="uthr-20260331.xsd#ConsolidatedStatementsofComprehensiveIncome"/>
  <link:calculationLink xlink:role="http://www.unither.com/role/ConsolidatedStatementsofComprehensiveIncome" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019d1dc9-bd6a-7ad1-9995-99a31b821c7d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent_019d1dc9-bd6a-772d-9a5f-d1c6d7888e46" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019d1dc9-bd6a-7ad1-9995-99a31b821c7d" xlink:to="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent_019d1dc9-bd6a-772d-9a5f-d1c6d7888e46" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_019d1dc9-bd6a-7863-b98a-05c950312b55" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019d1dc9-bd6a-7ad1-9995-99a31b821c7d" xlink:to="loc_us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_019d1dc9-bd6a-7863-b98a-05c950312b55" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent_019d1dc9-bd6a-73a5-a8ab-aac2bb478238" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTax_019d1dc9-bd6a-781b-acf2-c2f8e13e5432" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTax"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent_019d1dc9-bd6a-73a5-a8ab-aac2bb478238" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansNetOfTax_019d1dc9-bd6a-781b-acf2-c2f8e13e5432" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax_019d1dc9-bd6a-748e-ad5c-5641c8b6d8d9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent_019d1dc9-bd6a-73a5-a8ab-aac2bb478238" xlink:to="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax_019d1dc9-bd6a-748e-ad5c-5641c8b6d8d9" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_019d1dc9-bd6a-7588-92b7-10d0a5163539" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax_019d1dc9-bd6a-7f11-bcee-e57f1528e51f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_019d1dc9-bd6a-7588-92b7-10d0a5163539" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax_019d1dc9-bd6a-7f11-bcee-e57f1528e51f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsNetOfTax_019d1dc9-bd6a-761a-bc44-2b9f014d64e5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsNetOfTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent_019d1dc9-bd6a-7588-92b7-10d0a5163539" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeReclassificationAdjustmentsNetOfTax_019d1dc9-bd6a-761a-bc44-2b9f014d64e5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_019d1dc9-bd6a-7082-a6bb-d567ab6f4fbc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019d1dc9-bd6a-7831-a2a5-573a120e96f6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_019d1dc9-bd6a-7082-a6bb-d567ab6f4fbc" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019d1dc9-bd6a-7831-a2a5-573a120e96f6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019d1dc9-bd6a-74c0-952b-37fa3c133c4e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTax_019d1dc9-bd6a-7082-a6bb-d567ab6f4fbc" xlink:to="loc_us-gaap_NetIncomeLoss_019d1dc9-bd6a-74c0-952b-37fa3c133c4e" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.unither.com/role/ConsolidatedStatementsofCashFlows" xlink:type="simple" xlink:href="uthr-20260331.xsd#ConsolidatedStatementsofCashFlows"/>
  <link:calculationLink xlink:role="http://www.unither.com/role/ConsolidatedStatementsofCashFlows" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d1dc9-bd6a-7572-b8cb-bfa051acca27" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019d1dc9-bd6a-797e-b9c5-8ea2d20fb3c4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d1dc9-bd6a-7572-b8cb-bfa051acca27" xlink:to="loc_us-gaap_NetIncomeLoss_019d1dc9-bd6a-797e-b9c5-8ea2d20fb3c4" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_019d1dc9-bd6a-7951-bf90-bbfc5d01578f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d1dc9-bd6a-7572-b8cb-bfa051acca27" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_019d1dc9-bd6a-7951-bf90-bbfc5d01578f" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_019d1dc9-bd6a-77bb-afc9-903eb02773ce" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensation"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d1dc9-bd6a-7572-b8cb-bfa051acca27" xlink:to="loc_us-gaap_ShareBasedCompensation_019d1dc9-bd6a-77bb-afc9-903eb02773ce" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss_019d1dc9-bd6a-7479-80eb-7ae0262c052a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss"/>
    <link:calculationArc order="4" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d1dc9-bd6a-7572-b8cb-bfa051acca27" xlink:to="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGainLoss_019d1dc9-bd6a-7479-80eb-7ae0262c052a" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019d1dc9-bd6a-7a0f-8c17-e7469e255cd6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredIncomeTaxExpenseBenefit"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d1dc9-bd6a-7572-b8cb-bfa051acca27" xlink:to="loc_us-gaap_DeferredIncomeTaxExpenseBenefit_019d1dc9-bd6a-7a0f-8c17-e7469e255cd6" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNoncashIncomeExpense_019d1dc9-bd6a-7a90-b71f-bcf105887e49" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherNoncashIncomeExpense"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d1dc9-bd6a-7572-b8cb-bfa051acca27" xlink:to="loc_us-gaap_OtherNoncashIncomeExpense_019d1dc9-bd6a-7a90-b71f-bcf105887e49" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_019d1dc9-bd6a-7e40-80fa-485be1509778" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsReceivable"/>
    <link:calculationArc order="7" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d1dc9-bd6a-7572-b8cb-bfa051acca27" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsReceivable_019d1dc9-bd6a-7e40-80fa-485be1509778" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInInventories_019d1dc9-bd6a-7008-b903-0404e74a54c2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInInventories"/>
    <link:calculationArc order="8" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d1dc9-bd6a-7572-b8cb-bfa051acca27" xlink:to="loc_us-gaap_IncreaseDecreaseInInventories_019d1dc9-bd6a-7008-b903-0404e74a54c2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_019dd9ec-3e3b-7f9e-ad7b-0403bdf733c8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities"/>
    <link:calculationArc order="9" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d1dc9-bd6a-7572-b8cb-bfa051acca27" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_019dd9ec-3e3b-7f9e-ad7b-0403bdf733c8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_019dd9ec-3e3b-7e95-ad47-27f983a8c9b2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet"/>
    <link:calculationArc order="10" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d1dc9-bd6a-7572-b8cb-bfa051acca27" xlink:to="loc_us-gaap_IncreaseDecreaseInOtherOperatingCapitalNet_019dd9ec-3e3b-7e95-ad47-27f983a8c9b2" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019d1dc9-bd6a-7357-9e18-364081b3754c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d1dc9-bd6a-7cab-80f5-4ea774904c38" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019d1dc9-bd6a-7357-9e18-364081b3754c" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d1dc9-bd6a-7cab-80f5-4ea774904c38" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d1dc9-bd6a-7cf9-bc74-1308ed2c32bb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019d1dc9-bd6a-7357-9e18-364081b3754c" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d1dc9-bd6a-7cf9-bc74-1308ed2c32bb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d1dc9-bd6a-7aad-9b15-ea06a3334df0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_019d1dc9-bd6a-7357-9e18-364081b3754c" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_019d1dc9-bd6a-7aad-9b15-ea06a3334df0" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d1dc9-bd6a-7e78-bcb7-bfc4fe3879ad" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019d1dc9-bd6a-7c55-97f5-3d46f4cd47f5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d1dc9-bd6a-7e78-bcb7-bfc4fe3879ad" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019d1dc9-bd6a-7c55-97f5-3d46f4cd47f5" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_uthr_AdvancePaymentRelatedToPropertyPlantAndEquipment_019d1dc9-bd6a-7833-9cec-02b1fef3c98d" xlink:href="uthr-20260331.xsd#uthr_AdvancePaymentRelatedToPropertyPlantAndEquipment"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d1dc9-bd6a-7e78-bcb7-bfc4fe3879ad" xlink:to="loc_uthr_AdvancePaymentRelatedToPropertyPlantAndEquipment_019d1dc9-bd6a-7833-9cec-02b1fef3c98d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_019d1dc9-bd6a-7ecf-bd35-1825e31aeff8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d1dc9-bd6a-7e78-bcb7-bfc4fe3879ad" xlink:to="loc_us-gaap_PaymentsToAcquireAvailableForSaleSecuritiesDebt_019d1dc9-bd6a-7ecf-bd35-1825e31aeff8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_019d1dc9-bd6a-7145-bf20-f276f037d41d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d1dc9-bd6a-7e78-bcb7-bfc4fe3879ad" xlink:to="loc_us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities_019d1dc9-bd6a-7145-bf20-f276f037d41d" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_019d89ef-899b-76da-8204-ed9ab2612d51" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt"/>
    <link:calculationArc order="5" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d1dc9-bd6a-7e78-bcb7-bfc4fe3879ad" xlink:to="loc_us-gaap_ProceedsFromSaleOfAvailableForSaleSecuritiesDebt_019d89ef-899b-76da-8204-ed9ab2612d51" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_uthr_PaymentsToAcquireEquitySecuritiesWithoutReadilyDeterminableFairValue_019d89ef-899b-7615-9f7d-edd591ce14c8" xlink:href="uthr-20260331.xsd#uthr_PaymentsToAcquireEquitySecuritiesWithoutReadilyDeterminableFairValue"/>
    <link:calculationArc order="6" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_019d1dc9-bd6a-7e78-bcb7-bfc4fe3879ad" xlink:to="loc_uthr_PaymentsToAcquireEquitySecuritiesWithoutReadilyDeterminableFairValue_019d89ef-899b-7615-9f7d-edd591ce14c8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d1dc9-bd6a-7dd2-8500-5b67791357fd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_019d1dc9-bd6a-7883-a760-e7ee77627f72" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <link:calculationArc order="1" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d1dc9-bd6a-7dd2-8500-5b67791357fd" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_019d1dc9-bd6a-7883-a760-e7ee77627f72" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfLinesOfCredit_019d1dc9-bd6a-7d63-aefd-7c2e0f260c22" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RepaymentsOfLinesOfCredit"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d1dc9-bd6a-7dd2-8500-5b67791357fd" xlink:to="loc_us-gaap_RepaymentsOfLinesOfCredit_019d1dc9-bd6a-7d63-aefd-7c2e0f260c22" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised_019d1dc9-bd6a-7254-a823-6e7a33c5ab92" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromStockOptionsExercised"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d1dc9-bd6a-7dd2-8500-5b67791357fd" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised_019d1dc9-bd6a-7254-a823-6e7a33c5ab92" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans_019d1dc9-bd6a-79b2-9c0e-63b8959ab333" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans"/>
    <link:calculationArc order="4" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d1dc9-bd6a-7dd2-8500-5b67791357fd" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlans_019d1dc9-bd6a-79b2-9c0e-63b8959ab333" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_019d1dc9-bd6a-7c22-b182-b4aa9c54160d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:calculationArc order="5" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_019d1dc9-bd6a-7dd2-8500-5b67791357fd" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_019d1dc9-bd6a-7c22-b182-b4aa9c54160d" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.unither.com/role/InvestmentsAvailableforSaleDebtSecuritiesDetails" xlink:type="simple" xlink:href="uthr-20260331.xsd#InvestmentsAvailableforSaleDebtSecuritiesDetails"/>
  <link:calculationLink xlink:role="http://www.unither.com/role/InvestmentsAvailableforSaleDebtSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_019d1dc9-bd6a-7bbd-9310-9f3d9f995005" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019d1dc9-bd6a-7512-9a71-8727b1e1276e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_019d1dc9-bd6a-7bbd-9310-9f3d9f995005" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019d1dc9-bd6a-7512-9a71-8727b1e1276e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_019d1dc9-bd6a-7f42-ac5f-a158c1bc4627" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_019d1dc9-bd6a-7bbd-9310-9f3d9f995005" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_019d1dc9-bd6a-7f42-ac5f-a158c1bc4627" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_019d1dc9-bd6a-7c75-a761-cc1da9a5ce98" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax"/>
    <link:calculationArc order="3" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestAfterAllowanceForCreditLoss_019d1dc9-bd6a-7bbd-9310-9f3d9f995005" xlink:to="loc_us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_019d1dc9-bd6a-7c75-a761-cc1da9a5ce98" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.unither.com/role/InvestmentsCurrentandNoncurrentofAvailableforSaleDebtSecuritiesDetails" xlink:type="simple" xlink:href="uthr-20260331.xsd#InvestmentsCurrentandNoncurrentofAvailableforSaleDebtSecuritiesDetails"/>
  <link:calculationLink xlink:role="http://www.unither.com/role/InvestmentsCurrentandNoncurrentofAvailableforSaleDebtSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019d1dc9-bd6a-72c9-9613-b72c6ad3727f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterestNoncurrent_019d1dc9-bd6a-7240-a769-619b4d523410" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterestNoncurrent"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019d1dc9-bd6a-72c9-9613-b72c6ad3727f" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterestNoncurrent_019d1dc9-bd6a-7240-a769-619b4d523410" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterestCurrent_019d1dc9-bd6a-7ab5-ab18-d1e833d25505" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterestCurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest_019d1dc9-bd6a-72c9-9613-b72c6ad3727f" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterestCurrent_019d1dc9-bd6a-7ab5-ab18-d1e833d25505" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.unither.com/role/InvestmentsAvailableforSaleDebtSecuritiesinUnrealizedLossPositionDetails" xlink:type="simple" xlink:href="uthr-20260331.xsd#InvestmentsAvailableforSaleDebtSecuritiesinUnrealizedLossPositionDetails"/>
  <link:calculationLink xlink:role="http://www.unither.com/role/InvestmentsAvailableforSaleDebtSecuritiesinUnrealizedLossPositionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_019d1dc9-bd6a-7c9a-acba-4c818e782411" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_019d1dc9-bd6a-7bdc-a6df-ce100c1bd15e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_019d1dc9-bd6a-7c9a-acba-4c818e782411" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger_019d1dc9-bd6a-7bdc-a6df-ce100c1bd15e" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_019d1dc9-bd6a-7acd-b9b5-393e7c7d7c93" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPosition_019d1dc9-bd6a-7c9a-acba-4c818e782411" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months_019d1dc9-bd6a-7acd-b9b5-393e7c7d7c93" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_019d1dc9-bd6a-7f9b-a49e-c96b40ed0226" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_019d1dc9-bd6a-7f57-986b-35637bf77ae3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_019d1dc9-bd6a-7f9b-a49e-c96b40ed0226" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss_019d1dc9-bd6a-7f57-986b-35637bf77ae3" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_019d1dc9-bd6a-7af8-8eed-ac9e80750413" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss_019d1dc9-bd6a-7f9b-a49e-c96b40ed0226" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss_019d1dc9-bd6a-7af8-8eed-ac9e80750413" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.unither.com/role/InvestmentsContractualMaturitiesofAvailableforSaleMarketableInvestmentsDetails" xlink:type="simple" xlink:href="uthr-20260331.xsd#InvestmentsContractualMaturitiesofAvailableforSaleMarketableInvestmentsDetails"/>
  <link:calculationLink xlink:role="http://www.unither.com/role/InvestmentsContractualMaturitiesofAvailableforSaleMarketableInvestmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019d1dc9-bd6a-7f7d-aedf-5c778f5688bc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis_019d1dc9-bd6a-7ca9-aabb-7f29a8a5c633" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019d1dc9-bd6a-7f7d-aedf-5c778f5688bc" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis_019d1dc9-bd6a-7ca9-aabb-7f29a8a5c633" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_uthr_DebtSecuritiesAvailableForSaleMaturityAllocatedAndSingleMaturityDateRollingYearOneThroughThreeAmortizedCostBasis_019d1dc9-bd6a-7d7e-a0db-77aac82e8db8" xlink:href="uthr-20260331.xsd#uthr_DebtSecuritiesAvailableForSaleMaturityAllocatedAndSingleMaturityDateRollingYearOneThroughThreeAmortizedCostBasis"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_019d1dc9-bd6a-7f7d-aedf-5c778f5688bc" xlink:to="loc_uthr_DebtSecuritiesAvailableForSaleMaturityAllocatedAndSingleMaturityDateRollingYearOneThroughThreeAmortizedCostBasis_019d1dc9-bd6a-7d7e-a0db-77aac82e8db8" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_019d1dc9-bd6a-78e2-a310-63d50b0f2862" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue_019d1dc9-bd6a-76b7-a269-50fda2cd4b08" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_019d1dc9-bd6a-78e2-a310-63d50b0f2862" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue_019d1dc9-bd6a-76b7-a269-50fda2cd4b08" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_uthr_DebtSecuritiesAvailableForSaleMaturityAllocatedAndSingleMaturityDateRollingYearOneThroughYearThreeFairValue_019d1dc9-bd6a-75e3-9084-bd2474faafc2" xlink:href="uthr-20260331.xsd#uthr_DebtSecuritiesAvailableForSaleMaturityAllocatedAndSingleMaturityDateRollingYearOneThroughYearThreeFairValue"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_019d1dc9-bd6a-78e2-a310-63d50b0f2862" xlink:to="loc_uthr_DebtSecuritiesAvailableForSaleMaturityAllocatedAndSingleMaturityDateRollingYearOneThroughYearThreeFairValue_019d1dc9-bd6a-75e3-9084-bd2474faafc2" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.unither.com/role/FairValueMeasurementsDetails" xlink:type="simple" xlink:href="uthr-20260331.xsd#FairValueMeasurementsDetails"/>
  <link:calculationLink xlink:role="http://www.unither.com/role/FairValueMeasurementsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsFairValueDisclosure_019d3298-7bb7-7413-9bdc-022ed74ffcb8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019d3298-7bb7-7464-aaf1-ec69e7cb22eb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_019d3298-7bb7-7413-9bdc-022ed74ffcb8" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019d3298-7bb7-7464-aaf1-ec69e7cb22eb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent_019d3298-7bb7-7e5c-b17d-7ac0426db166" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_019d3298-7bb7-7413-9bdc-022ed74ffcb8" xlink:to="loc_us-gaap_EquitySecuritiesFvNiCurrentAndNoncurrent_019d3298-7bb7-7e5c-b17d-7ac0426db166" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019d3298-7bb7-7047-9dd1-8397a8f9ffb7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AssetsFairValueDisclosure_019d3298-7bb7-7413-9bdc-022ed74ffcb8" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019d3298-7bb7-7047-9dd1-8397a8f9ffb7" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesFairValueDisclosure_019d3298-7bb7-7c00-bb6c-f6bf657132ed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LiabilitiesFairValueDisclosure"/>
    <link:loc xlink:type="locator" xlink:label="loc_uthr_BusinessAcquisitionContingentConsiderationFairValueDisclosureLiability_019d3298-7bb7-7f53-b3a0-5d217b9bda21" xlink:href="uthr-20260331.xsd#uthr_BusinessAcquisitionContingentConsiderationFairValueDisclosureLiability"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_LiabilitiesFairValueDisclosure_019d3298-7bb7-7c00-bb6c-f6bf657132ed" xlink:to="loc_uthr_BusinessAcquisitionContingentConsiderationFairValueDisclosureLiability_019d3298-7bb7-7f53-b3a0-5d217b9bda21" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.unither.com/role/InventoriesDetails" xlink:type="simple" xlink:href="uthr-20260331.xsd#InventoriesDetails"/>
  <link:calculationLink xlink:role="http://www.unither.com/role/InventoriesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryNet_019d1dc9-bd6b-74b6-8062-45282526d8d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InventoryNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryRawMaterialsNetOfReserves_019d1dc9-bd6b-7547-9468-f47d3f91e445" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InventoryRawMaterialsNetOfReserves"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_019d1dc9-bd6b-74b6-8062-45282526d8d4" xlink:to="loc_us-gaap_InventoryRawMaterialsNetOfReserves_019d1dc9-bd6b-7547-9468-f47d3f91e445" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryWorkInProcessNetOfReserves_019d1dc9-bd6b-7bd9-b187-d8ed23b539cd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InventoryWorkInProcessNetOfReserves"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_019d1dc9-bd6b-74b6-8062-45282526d8d4" xlink:to="loc_us-gaap_InventoryWorkInProcessNetOfReserves_019d1dc9-bd6b-7bd9-b187-d8ed23b539cd" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryFinishedGoodsNetOfReserves_019d1dc9-bd6b-74b7-a53f-4bcc89e7057c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InventoryFinishedGoodsNetOfReserves"/>
    <link:calculationArc order="3" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_InventoryNet_019d1dc9-bd6b-74b6-8062-45282526d8d4" xlink:to="loc_us-gaap_InventoryFinishedGoodsNetOfReserves_019d1dc9-bd6b-74b7-a53f-4bcc89e7057c" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.unither.com/role/PropertyPlantandEquipmentScheduleofPropertyPlantandEquipmentDetails" xlink:type="simple" xlink:href="uthr-20260331.xsd#PropertyPlantandEquipmentScheduleofPropertyPlantandEquipmentDetails"/>
  <link:calculationLink xlink:role="http://www.unither.com/role/PropertyPlantandEquipmentScheduleofPropertyPlantandEquipmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_019d1dc9-bd6b-73c1-bbf4-71e80bf3e33f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_019d1dc9-bd6b-7ee6-aa07-9db36bde8beb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNet_019d1dc9-bd6b-73c1-bbf4-71e80bf3e33f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_019d1dc9-bd6b-7ee6-aa07-9db36bde8beb" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019d1dc9-bd6b-7172-9e06-d9e5dd16fa9c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentNet_019d1dc9-bd6b-73c1-bbf4-71e80bf3e33f" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_019d1dc9-bd6b-7172-9e06-d9e5dd16fa9c" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.unither.com/role/ShareBasedCompensationShareBasedCompensationExpenseDetails" xlink:type="simple" xlink:href="uthr-20260331.xsd#ShareBasedCompensationShareBasedCompensationExpenseDetails"/>
  <link:calculationLink xlink:role="http://www.unither.com/role/ShareBasedCompensationShareBasedCompensationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_019d1dc9-bd6b-7629-9a2d-48fad5140413" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019d1dc9-bd6b-7909-8298-196dbe47bc3c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_019d1dc9-bd6b-7629-9a2d-48fad5140413" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019d1dc9-bd6b-7909-8298-196dbe47bc3c" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_019d1dc9-bd6b-753d-b696-9af205bba86d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_019d1dc9-bd6b-7629-9a2d-48fad5140413" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_019d1dc9-bd6b-753d-b696-9af205bba86d" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.unither.com/role/StockholdersEquityScheduleofComponentsofBasicandDilutedEarningsLossPerCommonShareDetails" xlink:type="simple" xlink:href="uthr-20260331.xsd#StockholdersEquityScheduleofComponentsofBasicandDilutedEarningsLossPerCommonShareDetails"/>
  <link:calculationLink xlink:role="http://www.unither.com/role/StockholdersEquityScheduleofComponentsofBasicandDilutedEarningsLossPerCommonShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019d1dc9-be07-718a-be07-6a3442ee6dd3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019d1dc9-be07-7c5e-8069-81282b936f46" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019d1dc9-be07-718a-be07-6a3442ee6dd3" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_019d1dc9-be07-7c5e-8069-81282b936f46" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_019d1dc9-be07-7154-a658-de00e1690b75" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <link:calculationArc order="2" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_019d1dc9-be07-718a-be07-6a3442ee6dd3" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_019d1dc9-be07-7154-a658-de00e1690b75" xlink:type="arc"/>
  </link:calculationLink>
  <link:roleRef roleURI="http://www.unither.com/role/SegmentInformationGeneralDetails" xlink:type="simple" xlink:href="uthr-20260331.xsd#SegmentInformationGeneralDetails"/>
  <link:calculationLink xlink:role="http://www.unither.com/role/SegmentInformationGeneralDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_019d1dc9-be07-760b-8996-042d8615fc87" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GrossProfit"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019d1dc9-be07-7294-bf76-3a0be73619ea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:calculationArc order="1" weight="1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_019d1dc9-be07-760b-8996-042d8615fc87" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019d1dc9-be07-7294-bf76-3a0be73619ea" xlink:type="arc"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_019d1dc9-be07-7cab-aff4-75d9402c5f13" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:calculationArc order="2" weight="-1.0" xlink:arcrole="https://xbrl.org/2023/arcrole/summation-item" xlink:from="loc_us-gaap_GrossProfit_019d1dc9-be07-760b-8996-042d8615fc87" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_019d1dc9-be07-7cab-aff4-75d9402c5f13" xlink:type="arc"/>
  </link:calculationLink>
</link:linkbase>
