diff --git a/Common/System/Display.cpp b/Common/System/Display.cpp
index 13a734087d..5cb0a4bee4 100644
--- a/Common/System/Display.cpp
+++ b/Common/System/Display.cpp
@@ -54,6 +54,33 @@ DisplayProperties::DisplayProperties() {
 	rot_matrix.setIdentity();
 }
 
+bool DisplayProperties::Recalculate(int new_pixel_xres, int new_pixel_yres, float new_scale, float customScale) {
+	bool px_changed = false;
+	if (pixel_xres != new_pixel_xres) {
+		pixel_xres = new_pixel_xres;
+		px_changed = true;
+	}
+	if (pixel_yres != new_pixel_yres) {
+		pixel_yres = new_pixel_yres;
+		px_changed = true;
+	}
+
+	dpi_scale_real = new_scale;
+	dpi_scale = new_scale / customScale;
+	pixel_in_dps = 1.0f / dpi_scale;
+
+	int new_dp_xres = (int)(new_pixel_xres * dpi_scale);
+	int new_dp_yres = (int)(new_pixel_yres * dpi_scale);
+
+	if (new_dp_xres != dp_xres || new_dp_yres != dp_yres || px_changed) {
+		dp_xres = new_dp_xres;
+		dp_yres = new_dp_yres;
+		return true;
+	} else {
+		return false;
+	}
+}
+
 void DisplayProperties::Print() {
 	printf("dp_xres/yres: %d, %d\n", dp_xres, dp_yres);
 	printf("pixel_xres/yres: %d, %d\n", pixel_xres, pixel_yres);
diff --git a/Common/System/Display.h b/Common/System/Display.h
index a1afec1d7b..3c1bb436a6 100644
--- a/Common/System/Display.h
+++ b/Common/System/Display.h
@@ -39,6 +39,9 @@ struct DisplayProperties {
 
 	DisplayProperties();
 	void Print();
+
+	// Returns true if the dimensions changed.
+	bool Recalculate(int new_pixel_xres, int new_pixel_yres, float new_scale, float customScale);
 };
 
 extern DisplayProperties g_display;
diff --git a/Common/System/NativeApp.h b/Common/System/NativeApp.h
index 9308cf1bf2..8eef162c5b 100644
--- a/Common/System/NativeApp.h
+++ b/Common/System/NativeApp.h
@@ -90,5 +90,5 @@ void Native_NotifyWindowHidden(bool hidden);
 bool Native_IsWindowHidden();
 
 // TODO: Feels like this belongs elsewhere.
-bool Native_UpdateScreenScale(int width, int height);
+bool Native_UpdateScreenScale(int width, int height, float customScale);
 
diff --git a/Qt/QtMain.cpp b/Qt/QtMain.cpp
index d9618824d5..f188e23a57 100644
--- a/Qt/QtMain.cpp
+++ b/Qt/QtMain.cpp
@@ -549,7 +549,7 @@ QString MainUI::InputBoxGetQString(QString title, QString defaultValue) {
 }
 
 void MainUI::resizeGL(int w, int h) {
-	if (Native_UpdateScreenScale(w, h)) {
+	if (Native_UpdateScreenScale(w, h, 1.0f)) {
 		System_PostUIMessage(UIMessage::GPU_RENDER_RESIZED);
 	}
 	xscale = w / this->width();
diff --git a/SDL/SDLMain.cpp b/SDL/SDLMain.cpp
index 7a553df63e..8484fc8133 100644
--- a/SDL/SDLMain.cpp
+++ b/SDL/SDLMain.cpp
@@ -779,7 +779,7 @@ static void ProcessSDLEvent(SDL_Window *window, const SDL_Event &event, InputSta
 			bool fullscreen = (window_flags & SDL_WINDOW_FULLSCREEN);
 
 			// This one calls NativeResized if the size changed.
-			Native_UpdateScreenScale(new_width_px, new_height_px);
+			Native_UpdateScreenScale(new_width_px, new_height_px, 1.0f);
 
 			// Set variable here in case fullscreen was toggled by hotkey
 			if (g_Config.UseFullScreen() != fullscreen) {
@@ -1436,7 +1436,7 @@ int main(int argc, char *argv[]) {
 
 	float dpi_scale = 1.0f / (g_ForcedDPI == 0.0f ? g_DesktopDPI : g_ForcedDPI);
 
-	Native_UpdateScreenScale(w * g_DesktopDPI, h * g_DesktopDPI);
+	Native_UpdateScreenScale(w * g_DesktopDPI, h * g_DesktopDPI, 1.0f);
 
 	bool mainThreadIsRender = g_Config.iGPUBackend == (int)GPUBackend::OPENGL;
 
diff --git a/UI/NativeApp.cpp b/UI/NativeApp.cpp
index ed9cb7227e..8dca521881 100644
--- a/UI/NativeApp.cpp
+++ b/UI/NativeApp.cpp
@@ -1512,16 +1512,12 @@ bool Native_IsWindowHidden() {
 
 static bool IsWindowSmall(int pixelWidth, int pixelHeight) {
 	// Can't take this from config as it will not be set if windows is maximized.
-	int w = (int)(pixelWidth * g_display.dpi_scale);
-	int h = (int)(pixelHeight * g_display.dpi_scale);
+	int w = (int)(pixelWidth * g_display.dpi_scale_real);
+	int h = (int)(pixelHeight * g_display.dpi_scale_real);
 	return g_Config.IsPortrait() ? (h < 480 + 80) : (w < 480 + 80);
 }
 
-bool Native_UpdateScreenScale(int pixel_width, int pixel_height) {
-	bool smallWindow;
-
-	const bool px_changed = g_display.pixel_xres != pixel_width || g_display.pixel_yres != pixel_height;
-
+bool Native_UpdateScreenScale(int pixel_width, int pixel_height, float customScale) {
 	float g_logical_dpi = System_GetPropertyFloat(SYSPROP_DISPLAY_LOGICAL_DPI);
 	float dpi = System_GetPropertyFloat(SYSPROP_DISPLAY_DPI);
 
@@ -1532,34 +1528,15 @@ bool Native_UpdateScreenScale(int pixel_width, int pixel_height) {
 		g_logical_dpi = 96.0f;
 	}
 
-	g_display.dpi_scale_real = g_logical_dpi / dpi;
-	g_display.dpi_scale = g_display.dpi_scale_real;
-
-	float scaleFactor = 1.0f;
-
-	smallWindow = IsWindowSmall(pixel_width, pixel_height);
+	bool smallWindow = IsWindowSmall(pixel_width, pixel_height);
 	if (smallWindow) {
-		scaleFactor = 0.5f;
+		customScale *= 0.5f;
 	}
 
-	// No need to change ".dpi" here.
-	g_display.dpi_scale /= scaleFactor;
-
-	g_display.pixel_in_dps = 1.0f / g_display.dpi_scale;
-
-	int new_dp_xres = (int)(pixel_width * g_display.dpi_scale);
-	int new_dp_yres = (int)(pixel_height * g_display.dpi_scale);
-
-	const bool dp_changed = new_dp_xres != g_display.dp_xres || new_dp_yres != g_display.dp_yres;
-
-	if (!dp_changed && !px_changed) {
+	if (g_display.Recalculate(pixel_width, pixel_height, g_logical_dpi / dpi, customScale)) {
+		NativeResized();
+		return true;
+	} else {
 		return false;
 	}
-
-	g_display.dp_xres = new_dp_xres;
-	g_display.dp_yres = new_dp_yres;
-	g_display.pixel_xres = pixel_width;
-	g_display.pixel_yres = pixel_height;
-	NativeResized();
-	return true;
 }
diff --git a/UWP/App.cpp b/UWP/App.cpp
index 49eb8cd976..67bafebe0a 100644
--- a/UWP/App.cpp
+++ b/UWP/App.cpp
@@ -330,7 +330,7 @@ void App::OnWindowSizeChanged(CoreWindow^ sender, WindowSizeChangedEventArgs^ ar
 
 	PSP_CoreParameter().pixelWidth = (int)(width * scale);
 	PSP_CoreParameter().pixelHeight = (int)(height * scale);
-	if (Native_UpdateScreenScale((int)width, (int)height)) {
+	if (Native_UpdateScreenScale((int)width, (int)height, 1.0f)) {
 		System_PostUIMessage(UIMessage::GPU_DISPLAY_RESIZED);
 	}
 }
diff --git a/Windows/MainWindow.cpp b/Windows/MainWindow.cpp
index 403a43d51c..f0dc681c5c 100644
--- a/Windows/MainWindow.cpp
+++ b/Windows/MainWindow.cpp
@@ -298,7 +298,7 @@ namespace MainWindow
 
 		DEBUG_LOG(Log::System, "Pixel width/height: %dx%d", PSP_CoreParameter().pixelWidth, PSP_CoreParameter().pixelHeight);
 
-		if (Native_UpdateScreenScale(width, height)) {
+		if (Native_UpdateScreenScale(width, height, 1.0f)) {
 			System_PostUIMessage(UIMessage::GPU_DISPLAY_RESIZED);
 			System_PostUIMessage(UIMessage::GPU_RENDER_RESIZED);
 		}