DeviTestPPI calculator
Enter a resolution and a diagonal size to get pixel density, aspect ratio and the real width and height of the screen.
Pixel density PPI
Aspect ratio
Width × height
In centimeters
Total pixels
Sharpness
What PPI means
PPI (pixels per inch) tells you how many pixels fit in one inch of the screen. Higher PPI means smaller pixels and sharper text. It's calculated from the diagonal resolution — the square root of width² + height² — divided by the diagonal size in inches.
How much PPI do you need?
- Phones (25–35 cm away): around 300 PPI or more looks sharp to most people.
- Laptops and monitors (50–70 cm away): 100–140 PPI is comfortable; 160+ looks very crisp.
- TVs (2–3 m away): PPI is low, but distance makes up for it. Viewing distance matters more than the number.
Why "Use my screen resolution" might differ from the spec sheet
Browsers report a scaled resolution multiplied by the device pixel ratio. On most phones the result matches the real panel, but some devices round the numbers or use display scaling, so check your manufacturer's specs if the values look slightly off.