iPhone 12 Screen Ruler
This page provides a ruler calibrated specifically for the iPhone 12. The iPhone 12 has a 6.1-inch screen with a pixel density of 460 PPI (pixels per inch), which translates to approximately 181 pixels per centimeter. Use the ruler above to measure real-world objects directly on your iPhone 12 screen with accuracy within 0.5mm after calibration.
The iPhone 12 marked Apple's return to flat sides, and that squared-off aluminum edge doubles as a handy straightedge when you press an object against the screen. Its 6.1-inch Super Retina XDR OLED runs at 460 PPI and 2532x1170, identical in sharpness to the iPhone 13, so calibrated ruler markings render accurately down to the millimeter. The Ceramic Shield front lets you rest coins or cards directly on the display for calibration without scratches.
iPhone 12 Display Specifications
Screen Size
6.1"
Pixel Density
460 PPI
Device Type
smartphone
Pixels per CM
181
How to Measure on Your iPhone 12
- Open the ruler on your iPhone 12 using any web browser (Safari, Chrome, or Firefox all work).
- Calibrate by placing a credit card or known-size object on the screen and adjusting the calibration slider until the on-screen outline matches the object exactly.
- Measure by placing any object against the ruler markings. The ruler displays centimeters, millimeters, and inches simultaneously.
- Your calibration is saved automatically in your browser for 30 days, so the ruler stays accurate on return visits.
Why PPI Matters for Screen Measurement
PPI (Pixels Per Inch) determines how large each pixel appears on your screen. The iPhone 12's 460 PPI means 460 tiny dots fit within one physical inch of screen space. A higher PPI means smaller pixels, sharper text, and more precise ruler markings.
For comparison, a typical desktop monitor has around 96 PPI, while the iPhone 12 at 460 PPI offers 4.8x the pixel density. This higher density allows the on-screen ruler to display finer graduation marks and more accurate measurements.