How to use the Screen Size Calculator
- Enter the diagonal size in inches.
- Choose the aspect ratio, or use the resolution for a custom ratio.
- Enter the resolution to get pixel density (PPI).
What does this tool do?
Screens are sold by their diagonal, but the width and height depend on the aspect ratio. A 55-inch 16:9 TV is about 47.9 × 27 inches; a 27-inch 21:9 ultrawide is shorter than a 27-inch 16:9.
Pixel density (pixels per inch) tells you how sharp a screen looks: a 27-inch 1440p monitor is about 109 PPI, while phones often exceed 400.
Why use it?
- Common ratios built in.
- Pixel density and pitch.
- Centimetres too.
The formula
Privacy
The calculation happens instantly in your browser. The numbers you enter are not sent to our servers or saved. There's no account to create and nothing to install.
Last reviewed by the M2Toolkit team.