Screen PPI Calculator: Pixel Density of a Laptop Display
Pixel density tells you how sharp a screen looks. Enter the resolution and the diagonal size in inches.
How it works
PPI is the number of pixels along the diagonal divided by the diagonal length in inches. The pixel diagonal comes from the Pythagorean theorem: the square root of width squared plus height squared.
Dot pitch is the distance between two pixels: 25.4 mm divided by the PPI. Width and height in inches are the pixel counts divided by the PPI.
Questions and answers
What is a good PPI for a laptop?
At a normal laptop viewing distance most people stop seeing individual pixels somewhere around 200 PPI and above. A 14-inch 1920 x 1200 screen is about 162 PPI, which looks fine but not razor sharp.
Is higher PPI always better?
No. More pixels cost battery life and graphics performance. Past the point where you cannot see pixels, extra density adds little.
Does PPI depend on aspect ratio?
Only through the resolution. The formula uses the real pixel width and height, so it works for 16:9, 16:10, 3:2 and any other shape.