What Is My Screen Resolution?

This page reads your display straight from the browser: the screen resolution, the physical pixels behind it, the device pixel ratio, the size of this browser window and the aspect ratio. Web designers use it to test layouts, support teams ask for it when a page looks wrong, and buyers use the PPI figure to compare how sharp two screens are.

How to use this tool

1. Open the page — the numbers appear at once.
2. Optionally enter the screen diagonal in inches to get pixels per inch (PPI).
3. To compare another screen, type its resolution, such as 2560x1440, in the second box.
4. Use the table to look up the name of common resolutions.

Formula

physical pixels = CSS pixels × device pixel ratio; PPI = √(width² + height²) ÷ diagonal

Width and height are in physical pixels and the diagonal in inches. Dot pitch is 25.4 ÷ PPI millimetres. The aspect ratio divides width and height by their greatest common divisor; the nearest common ratio is shown when it is within 3%.

Example

A 27-inch 2560 × 1440 monitor has a diagonal of √(2560² + 1440²) ≈ 2,937 pixels, so its density is 2,937 ÷ 27 ≈ 108.8 PPI with a 16:9 ratio. A 24-inch Full HD screen reaches only about 91.8 PPI, which is why text looks a little softer on it.