Real Ruler - Accurate Measure

Real Ruler turns your screen into a ruler that measures at true physical size.

Most on-screen rulers are wrong because every device has a different pixel density. Real Ruler starts from a database of known devices and lets you calibrate against anything you already own, so a centimetre on screen is a real centimetre.

ACTUAL SIZE, NOT APPROXIMATE
Pick your device or calibrate by hand against a coin, a card, or a ruler you trust. Once it is set, it stays set.

MEASURE FROM ANY EDGE
Place a ruler along the left, right, top or bottom of the screen, or use more than one at a time, so you can line up whatever you are measuring the way that suits it.

GUIDE LINES
Drop a guide line anywhere and slide it into place to mark a measurement, compare two objects, or hold a reference while you work. Clear them in one tap.

TRACK COORDINATES
Turn on the crosshair to read exact positions as you move around the screen.

CENTIMETRES OR INCHES
Switch units instantly. Dark mode included.

NO ACCOUNT, NO INTERNET NEEDED
There is nothing to sign up for. The app does not read your contacts, photos or files, and measuring works entirely offline.

Real Ruler is supported by a single banner ad.