Screen Ruler
A ruler, calipers, protractor and bubble level for the screen in your hand.
Approximate scale. Match a known length before measuring real objects.
Quick start
- Open Calibrate in settings and select your device or adjust the scale against a physical ruler.
- Drag the green and amber calipers to the two edges you want to compare.
- Read the horizontal and vertical distances separately. Use Tools for angles or the bubble level.
Recheck calibration after changing browser zoom, display settings or device. On-screen numbers are not a guarantee of physical accuracy.
The interactive ruler needs JavaScript. The guides above work without it.