diff --git a/src/CalcViewModel/DataLoaders/UnitConverterDataConstants.h b/src/CalcViewModel/DataLoaders/UnitConverterDataConstants.h
index bd8cb169..7032b250 100644
--- a/src/CalcViewModel/DataLoaders/UnitConverterDataConstants.h
+++ b/src/CalcViewModel/DataLoaders/UnitConverterDataConstants.h
@@ -1,4 +1,4 @@
-// Copyright (c) Microsoft Corporation. All rights reserved.
+// Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
 namespace CalculatorApp
@@ -162,7 +162,8 @@ namespace CalculatorApp
             Data_Zebibytes = UnitStart + 162,
             Data_Zetabits = UnitStart + 163,
             Data_Zetabytes = UnitStart + 164,
-            UnitEnd = Data_Zetabytes
+            Area_Pyeong = UnitStart + 165,
+            UnitEnd = Area_Pyeong
         };
     }
 }
diff --git a/src/CalcViewModel/DataLoaders/UnitConverterDataLoader.cpp b/src/CalcViewModel/DataLoaders/UnitConverterDataLoader.cpp
index 45411c1d..cc8b6739 100644
--- a/src/CalcViewModel/DataLoaders/UnitConverterDataLoader.cpp
+++ b/src/CalcViewModel/DataLoaders/UnitConverterDataLoader.cpp
@@ -120,6 +120,12 @@ void UnitConverterDataLoader::LoadData()
 
                 for (auto itr = unitConversions.begin(); itr != unitConversions.end(); ++itr)
                 {
+                    if (idToUnit.find(itr->first) == idToUnit.end())
+                    {
+                        // Optional units will not be in idToUnit but can be in unitConversions.
+                        // For optional units that did not make it to the current set of units, just continue.
+                        continue;
+                    }
                     UCM::ConversionData parsedData = { 1.0, 0.0, false };
                     assert(itr->second > 0); // divide by zero assert
                     parsedData.ratio = unitFactor / itr->second;
@@ -175,6 +181,10 @@ void UnitConverterDataLoader::GetUnits(_In_ unordered_map<ViewMode, vector<Order
 
     bool useWattInsteadOfKilowatt = m_currentRegionCode == "GB";
 
+    // Use Pyeong, a Korean floorspace unit.
+    // https://en.wikipedia.org/wiki/Korean_units_of_measurement#Area
+    bool usePyeong = m_currentRegionCode == L"KP" || m_currentRegionCode == L"KR";
+    
     vector<OrderedUnit> areaUnits;
     areaUnits.push_back(OrderedUnit{ UnitConverterUnits::Area_Acre, GetLocalizedStringName(L"UnitName_Acre"), GetLocalizedStringName(L"UnitAbbreviation_Acre"), 9 });
     areaUnits.push_back(OrderedUnit{ UnitConverterUnits::Area_Hectare, GetLocalizedStringName(L"UnitName_Hectare"), GetLocalizedStringName(L"UnitAbbreviation_Hectare"), 4 });
@@ -190,6 +200,10 @@ void UnitConverterDataLoader::GetUnits(_In_ unordered_map<ViewMode, vector<Order
     areaUnits.push_back(OrderedUnit{ UnitConverterUnits::Area_Paper, GetLocalizedStringName(L"UnitName_Paper"), GetLocalizedStringName(L"UnitAbbreviation_Paper"), 12, false, false, true });
     areaUnits.push_back(OrderedUnit{ UnitConverterUnits::Area_SoccerField, GetLocalizedStringName(L"UnitName_SoccerField"), GetLocalizedStringName(L"UnitAbbreviation_SoccerField"),13, false, false, true });
     areaUnits.push_back(OrderedUnit{ UnitConverterUnits::Area_Castle, GetLocalizedStringName(L"UnitName_Castle"), GetLocalizedStringName(L"UnitAbbreviation_Castle"), 14, false, false, true });
+    if (usePyeong)
+    {
+        areaUnits.push_back(OrderedUnit{ UnitConverterUnits::Area_Pyeong, GetLocalizedStringName(L"UnitName_PYeong"), GetLocalizedStringName(L"UnitAbbreviation_Pyeong"), 15, false, false, false });
+    }
     unitMap.emplace(ViewMode::Area, areaUnits);
 
     vector<OrderedUnit> dataUnits;
@@ -384,6 +398,7 @@ void UnitConverterDataLoader::GetConversionData(_In_ unordered_map<ViewMode, uno
             { ViewMode::Area, UnitConverterUnits::Area_Paper, 0.06032246 },
             { ViewMode::Area, UnitConverterUnits::Area_SoccerField, 10869.66 },
             { ViewMode::Area, UnitConverterUnits::Area_Castle, 100000 },
+            { ViewMode::Area, UnitConverterUnits::Area_Pyeong, 3.305785 }, // apprx of 400/121
 
             { ViewMode::Data, UnitConverterUnits::Data_Bit, 0.000000125 },
             { ViewMode::Data, UnitConverterUnits::Data_Byte, 0.000001 },
diff --git a/src/Calculator/Resources/en-US/Resources.resw b/src/Calculator/Resources/en-US/Resources.resw
index a9f3682f..0ae88c70 100644
--- a/src/Calculator/Resources/en-US/Resources.resw
+++ b/src/Calculator/Resources/en-US/Resources.resw
@@ -3379,4 +3379,12 @@
     <value>Microsoft Services Agreement</value>
     <comment>Displayed on a link to the Microsoft Services Agreement in the about this app information</comment>
   </data>
-</root>
+  <data name="UnitAbbreviation_Pyeong" xml:space="preserve">
+    <value>Pyeong</value>
+    <comment>An abbreviation for a measurement unit of area.</comment>
+  </data>
+  <data name="UnitName_Pyeong" xml:space="preserve">
+    <value>Pyeong</value>
+    <comment>A measurement unit for area.</comment>
+  </data>
+</root>
\ No newline at end of file
diff --git a/src/Calculator/Resources/ko-KR/Resources.resw b/src/Calculator/Resources/ko-KR/Resources.resw
index 6a9c6903..de9cbde8 100644
--- a/src/Calculator/Resources/ko-KR/Resources.resw
+++ b/src/Calculator/Resources/ko-KR/Resources.resw
@@ -2907,4 +2907,12 @@
     <value>Microsoft 서비스 계약</value>
     <comment>Displayed on a link to the Microsoft Services Agreement in the about this app information</comment>
   </data>
+  <data name="UnitAbbreviation_Pyeong" xml:space="preserve">
+    <value>평</value>
+    <comment>An abbreviation for a measurement unit of area.</comment>
+  </data>
+  <data name="UnitName_Pyeong" xml:space="preserve">
+    <value>평</value>
+    <comment>A measurement unit for area.</comment>
+  </data>
 </root>
\ No newline at end of file