Screen PPI Calculator

Pixels Per Inch (PPI) — also called pixel density — measures how many pixels fit into one linear inch of a display. Higher PPI means sharper images. Apple introduced the term 'Retina Display' for screens with PPI high enough that individual pixels are not distinguishable at a typical viewing distance (generally ≥ 200–300 PPI depending on screen size and viewing distance).

1. 1Diagonal pixel count = √(width² + height²) in pixels
2. 2PPI = diagonal pixel count / diagonal screen size in inches
3. 3Dot pitch = 25.4 mm / PPI — physical size of one pixel
4. 4Total megapixels = (width × height) / 1,000,000