Screen Rulers by Device

Pick your device for a pre-calibrated ruler that accounts for your screen's PPI automatically. Every screen has a different pixel density — a 1 cm line on an iPhone is a different number of pixels than on an iPad. These device pages skip calibration and show an accurate ruler instantly.

Don't see your device? Use the general screen ruler and calibrate with a credit card.

How device-specific rulers work

Each device page uses the manufacturer's published PPI (pixels per inch) and screen resolution to render a ruler at true physical size. No manual calibration needed — just open the page on the matching device. If you're on a different screen than the one listed, the ruler falls back to credit-card calibration for the same accuracy.

Open general ruler →Browse the full Device Specs Database →

Apple iPhone

Apple iPad

Samsung Galaxy

Other Android