Example drawing · open your own photo to measure it

Golden Mean Gauge

Click Open photo (or drop a picture onto the gauge), put the two outer points on any two landmarks, and the middle point shows where the golden section falls between them. Or try one of the examples under the picture.

Open photo

Gap ratio, long ÷ short

1 : 1.618

gauge opening: —

Gauge size Use this when a span is out of reach. The tips stay put and the gauge re-hinges to fit.

Gauge opacity Show points and lines

How to use

Drag the gauge to move it.
Drag either tip (the rings) to open or close the gauge on its rivets; the other tip stays put.
Drag empty space to pan. Zoom with + and −, by pinching, or with Ctrl (⌘ on a Mac) and the scroll wheel.
Arrow keys open and close the gauge in fine steps (click the picture first; hold Shift for bigger steps).
You can also drop or paste a photo onto the gauge.
Save picture downloads your photo with the gauge on it, to keep or share. Reset removes your photo and starts again.

Your photo stays on your device. Nothing is uploaded.