diff --git a/Source/UI/MiniPartyUsableArea.cpp b/Source/UI/MiniPartyUsableArea.cpp
new file mode 100644
index 0000000..82d9552
--- /dev/null
+++ b/Source/UI/MiniPartyUsableArea.cpp
@@ -0,0 +1,18 @@
+#include "UI/MiniPartyGrid.h"
+#include "UI/Window/UIWindow.h"
+#include "UI/Window/UIWindowMgr.h"
+
+// OFFSET: 0x00A918B0
+// FUNCTION: fn_17166
+void UIWindowMgr::GetMiniPartyUsableArea(RECT* area) {
+  const int height = this->unknown_0480;
+  int top = static_cast<int>(height * 0.3f);
+  if (UIWindow* window = g_windowMgr.LookupWindow(307)) {
+    top = window->geometry.height;
+  }
+
+  area->right = this->unknown_047C;
+  area->top = top;
+  area->left = 0;
+  area->bottom = height - g_miniPartyCellHeight * 3;
+}
diff --git a/Source/UI/Window/UIWindowMgr.h b/Source/UI/Window/UIWindowMgr.h
index e73ce1e..57274e6 100644
--- a/Source/UI/Window/UIWindowMgr.h
+++ b/Source/UI/Window/UIWindowMgr.h
@@ -422,6 +422,7 @@ public:
   void Shutdown();
   void SetScreenSize(int width, int height);
   UIWindow* LookupWindow(int id);
+  void GetMiniPartyUsableArea(RECT* area);
   void Schedule(UIWindow* window);
   void Destroy(UIWindow* window);
   void ForgetWindowReferences(UIWindow* removed);
diff --git a/data/compile.json b/data/compile.json
index de54914..d86737a 100644
--- a/data/compile.json
+++ b/data/compile.json
@@ -600,6 +600,7 @@
   "Source/UI/MiniPartyGrid.cpp": 2,
   "Source/UI/MiniPartyManager.cpp": 2,
   "Source/UI/MiniPartyPlacement.cpp": 2,
+  "Source/UI/MiniPartyUsableArea.cpp": 2,
   "Source/UI/Party/UIAdvenPartyBoardWnd.cpp": 2,
   "Source/UI/Party/UIApplyForPartyWnd.cpp": 2,
   "Source/UI/Party/UIPartyInfoWnd.cpp": 2,