Tool

PPI & size calculator

Enter a resolution and the diagonal size to get pixel density (PPI), dot pitch and the real physical dimensions of the panel.

Width (px)Height (px)Diagonal (in)

Pixel density: —; PPI
Dot pitch: —; mm
Width: —; inches
Height: —; inches

What is PPI?

Pixels per inch (PPI) measures how densely packed a display's pixels are. It is calculated from the diagonal pixel count divided by the diagonal physical size: PPI = √(width² + height²) ÷ diagonal. Higher PPI means sharper text and images because individual pixels become too small to distinguish.

As a rough guide: desktop monitors sit around 80–110 PPI, "retina"-class laptops around 200–260 PPI, and modern phones 400–500+ PPI. Dot pitch is the same idea expressed as the distance between pixels in millimetres.