EasyRuler: Screen Ruler

Check the size of small everyday objects with the iPhone or iPad you already have with you. EasyRuler keeps the whole screen available for measuring, with the controls there when you need them.

A ruler across the whole screen
Read metric and imperial markings side by side. Use the clean static ruler, or switch to two movable markers and read the distance between them. Turn your device to use portrait or landscape.

Match the whole scale
Place a real ruler alongside your device, align the zero marks and adjust the full visible scale. Compare the far end and the marks in between as the screen updates. Save when ready, or cancel without replacing your previous calibration. A standard bank card reference is available when no ruler is nearby.

Fine adjustments, fewer accidental taps
Use the plus and minus controls to move either marker in 0.1 mm steps. Lock the aligned markers, then tap a blank area to hide or show the unlock button. When unlocked, a tap on the ruler hides or shows the normal controls.

Simple by design
Pay once to download; all features are included. No ads, subscriptions, in-app purchases or accounts. Measuring and calibration work offline. Settings are saved locally, and your measurements are not uploaded to us. The interface follows your device's light or dark appearance.

Before measuring
Accuracy depends on the device, your calibration reference and how you align it. The 0.1 mm adjustment step does not guarantee 0.1 mm physical accuracy. Use a reliable real ruler and check several marks before relying on a reading. The available measuring span depends on your screen size. EasyRuler is for everyday checks on the built-in screen, not professional or safety-critical measurement. External displays are not supported.

For iPhone and iPad with iOS or iPadOS 16 or later.