Free image utility
PPI Calculator
Calculate the pixel density of a screen from its resolution and diagonal size.
PPI
91.79
- Total pixels
- 2,073,600
- Megapixels
- 2.07 MP
- Aspect ratio
- 16:9
- Pixel pitch
- 0.2767 mm
- Diagonal
- 2,203 px · 24 in
√(1,920² + 1,080²) ÷ 24 in = 91.79 PPI
What PPI means
PPI (pixels per inch) is how many pixels fit along one inch of a screen. It describes how fine the pixel grid is — and so how sharp text and images look.
How screen PPI is calculated
Screens are sold by their diagonal, so the calculation uses the diagonal too. First find the diagonal in pixels with Pythagoras, then divide by the diagonal in inches:
PPI = √(width² + height²) ÷ diagonal inches
| Screen | Resolution | PPI |
|---|---|---|
| 24″ monitor | 1920 × 1080 | 91.79 |
| 27″ monitor | 2560 × 1440 | 108.79 |
| 27″ monitor | 3840 × 2160 | 163.18 |
| 13.3″ laptop | 2560 × 1600 | 226.98 |
PPI vs resolution
Resolution is the pixel count (for example 1920 × 1080); PPI is how densely those pixels are packed. Two screens with the same resolution can have very different PPI if they are different sizes. The shape of the resolution is its aspect ratio — see the Aspect Ratio Calculator.
PPI vs DPI
PPI describes pixels on screens and in digital images. DPI describes print output. If you're preparing an image for paper, the DPI Calculator is the right tool.
Frequently asked questions
What is the PPI of a 24-inch 1080p monitor?
About 91.79 PPI. The diagonal is √(1920² + 1080²) ≈ 2202.9 pixels, divided by 24 inches.
Is higher PPI better?
Higher PPI means smaller pixels and sharper text at the same viewing distance. Phones are viewed close and often exceed 400 PPI; desktop monitors are commonly between 90 and 220 PPI.
Does PPI change with screen size?
Yes. The same resolution on a larger screen spreads pixels further apart, so PPI drops.