PPI Calculator (Pixels Per Inch)

PPI (pixels per inch) measures how densely pixels are packed on a screen. Higher PPI means sharper text and images at the same viewing distance.

Take the diagonal in pixels, sqrt(width^2 + height^2), then divide by the screen's diagonal in inches. For 1920x1080 on a 24-inch monitor that comes out to about 91.8 PPI.

There is no universal Retina threshold because perceived sharpness also depends on viewing distance and eyesight. This calculator uses internal labels: Retina-class above 300 PPI, High-density from 200 to 300, Standard from 100 to 200, and Low-density below 100. Treat them as descriptive bands, not display standards.

Manufacturers may round dimensions or use the active panel area rather than the marketed diagonal. Small differences in the diagonal therefore change the result. Check the panel's exact pixel dimensions and measured diagonal when you need to reproduce a published PPI value.

No. PPI measures image or display pixels per inch. DPI measures physical printer dots per inch, and a printer may use several dots to reproduce one image pixel. People sometimes use the terms loosely, but they are not interchangeable specifications.