Screen PPI Calculator
Work out pixels-per-inch (PPI), dot pitch and screen density from a screen's resolution and diagonal size.
For general use. PPI, dot pitch and pixel counts are calculated directly from the resolution and diagonal size you enter, check your device's exact specifications for the manufacturer's own figures.
Enter your screen specs
Your PPI, dot pitch and total pixel count appear here as you type.
How PPI is calculated
Pixels-per-inch (PPI) measures screen density, how tightly packed the pixels are. We first work out the diagonal pixel count using Pythagoras' theorem, the square root of (width² + height²), then divide by the diagonal size in inches. Dot pitch is the physical size of a single pixel in millimetres (25.4 ÷ PPI), and total pixels is simply width × height, shown in megapixels. Higher PPI means a sharper image at a given viewing distance, Apple popularised the term "Retina" for phone screens around 300 PPI and above, the point at which most people can no longer distinguish individual pixels at normal reading distance.
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