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Math

Pixel Density Calculator

Calculate pixels per inch, physical screen dimensions and pixel pitch from resolution and diagonal size.

Exact method explained belowEditable inputs

Set up your calculation

Runs on your device

SOLUTION

Your result

Let’s calculate.

Use the Calculate button to see your result.

Review the method below for assumptions and conventions.

How to use this tool

  1. Enter horizontal pixels, vertical pixels, screen diagonal (inches).
  2. Select Calculate to view the result.
  3. Check the method and assumptions below before using the result.

The method, explained

PPI = square root of (horizontal pixels² + vertical pixels²) ÷ diagonal inches. Physical width = horizontal pixels ÷ PPI. Pixel pitch = 25.4 ÷ PPI millimeters.

A WORKED EXAMPLE

A 1920 × 1080 screen with a 24-inch diagonal has approximately 91.79 PPI and is 20.92 inches wide.

What to keep in mind

Assumes square pixels and an accurately measured active-screen diagonal, excluding bezels. PPI alone does not measure perceived sharpness, viewing distance, color quality or software scaling.

Common questions

Is screen PPI the same as printer DPI?

No. Screen PPI counts pixels per inch; printer DPI describes ink-dot placement and is a different specification.

Does changing operating-system scaling change physical PPI?

No. Scaling changes interface size, not the physical pixel spacing.

Methodology maintained by ClarityKit. How these tools are built and checked.