Tablet calibration reference

iPad Pro 11-inch (M4) screen PPI

This tablet reference combines its 2420 × 1668 display, 11-inch diagonal, and estimated 264 PPI to give you a faster starting point for online-ruler calibration.

Open the ruler with a 11-inch estimate

Resolution

2420 × 1668

Screen diagonal

11"

Estimated PPI

264

How this iPad Pro 11-inch (M4) reference works

The reference combines this display’s 2420 × 1668 resolution with its 11-inch diagonal. PPI is the diagonal pixel count divided by the physical diagonal: sqrt(width² + height²) / diagonal inches. The 264 PPI figure is a rounded hardware-display specification, useful as a starting estimate rather than a browser measurement.

Browser CSS pixels, operating-system scaling, and browser zoom can all differ from the panel’s hardware pixels. That is why a screen specification cannot by itself guarantee a physical on-screen inch.

Calibrate on this tablet

Use the ruler in the same orientation and browser zoom that you will use for measuring. Verify the reference scale with a physical card after the estimate is applied.

Start with the 11-inch estimate, then compare the on-screen card guide with a physical standard card before relying on the ruler for a measurement. Recalibrate after changing zoom, display scaling, or the active screen.

Read the calibration guide or calculate PPI manually.

Related tablet PPI references

Compare similar displays when checking whether a saved calibration estimate is still appropriate for the screen in use.