Resolution & PPI Calculator

Calculate pixel density (PPI) for any display from its resolution and diagonal size. See physical dimensions, megapixels, dot pitch, and check your current screen stats.

Presets:
Wpx
×
Hpx
inches
91.79
PPI
Low DPI
Megapixels
2.07 MP
Aspect ratio
16:9
Physical size (in)
20.92" × 11.77"
Physical size (cm)
53.13 × 29.89 cm
Pixel area (total)
2,073,600 px
Dot pitch
0.28 mm

Frequently asked questions

What is PPI?

PPI (pixels per inch) is the number of individual pixels packed into one inch of a display. Higher PPI means sharper images — at 200+ PPI, individual pixels become invisible at normal viewing distance.

How is PPI calculated?

PPI = √(width² + height²) ÷ diagonal. For a 1920×1080 display with a 24" diagonal: √(1920² + 1080²) = 2202 pixels, divided by 24 = 91.8 PPI.

What is Retina display?

Apple coined "Retina" for displays where pixels are too dense to distinguish individually at typical viewing distance. Generally this starts around 220–300 PPI for phones and 200+ PPI for laptops.

What is dot pitch?

Dot pitch is the physical distance between the centres of adjacent pixels, measured in millimetres. It is the inverse of PPI — lower dot pitch = higher pixel density = sharper display.

Why does my OS report a different resolution than the physical pixels?

Modern high-DPI displays use a device pixel ratio (e.g. ×2 for Retina). The OS reports logical pixels (CSS pixels) which are a fraction of the physical pixels. The "Current display" section shows both.