diff --git a/calculator/test.js b/calculator/test.js
index 44d49e1..cda9b10 100644
--- a/calculator/test.js
+++ b/calculator/test.js
@@ -30,7 +30,7 @@ global.g = {
     return this;
   },
   setFontAlign: () => {},
-  stringWidth: (s) => s.length * 8 * (global.g._font_size || 1), // simple approximation
+  stringWidth: (s) => s.length * 5 * (global.g._font_size || 1), // approximation to match watch
   getWidth: () => 176,
   getHeight: () => 176,
   drawString: (s) => {