DPI / PPI Calculator

Formula

√(w²+h²)÷diagonal

Worked example

1920×1080 at 24in — about 91.79 PPI

Quick answer

What does the DPI / PPI Calculator do?

Calculate pixel density from resolution and diagonal screen size.

What is the DPI / PPI Calculator?

Calculate pixel density from resolution and diagonal screen size. Use it when you have the required inputs and want a deterministic, repeatable result with the calculation method visible.

How to use this calculator

Enter the values requested by the tool, keep units and time periods consistent, resolve any validation message, calculate, then review the primary answer together with the displayed formula and supporting values.

Formula and method

This calculator uses the deterministic formula √(w²+h²)÷diagonal. Enter the required values, then review the displayed substitution and result breakdown to verify the calculation.

Worked example

1920×1080 at 24in about 91.79 PPI

Common mistakes to avoid

Check units, decimal points, percentages, signs, date/time order, selector choices, and rounding. For important decisions, verify the result against an independent source or qualified professional when appropriate.