Measure from a photo
Open, drop or paste a photo, then calibrate against something of known size (a bank card is 85.6 mm, an A4 sheet 297 mm).
- Plane: click the 4 corners of a known rectangle. Corrects perspective, so the photo can be taken at an angle.
- Scale: mark one known length. Only accurate for a flat subject photographed straight-on.
Browsers can’t use LiDAR or AR depth (iOS Safari doesn’t expose it), so this measures on a photo with a reference, or on a satellite map. Accuracy depends on the reference, not the app.
Unit converter
Exact definitions: 1 in = 25.4 mm, 1 ft = 0.3048 m, 1 yd = 0.9144 m, 1 mi = 1609.344 m, 1 acre = 4046.8564224 m².