Pixel Density (PPI) Calculator
Pixels per inch of a screen from its resolution and diagonal, the size of each pixel, and the viewing distance beyond which individual pixels disappear.
Results
Pixel density
91.79
ppi
Pixel pitch
0.2767
mm
Total pixels
2.074
MP
Distance where single pixels stop being visible
95.1
cm
Screen width
53.1
cm
What this tool does
Pixel density is the number of pixels along the diagonal divided by the diagonal's length. Whether it is 'enough' depends on distance: someone with normal vision resolves about one arc-minute, so beyond the distance shown the pixels blur into a continuous image — which is why a 24-inch Full HD monitor looks soft at arm's length while a phone needs several times the density at 30 cm. The diagonal is the visible screen, not the frame.
Formula
PPI = √(w² + h²) ÷ diagonal · pitch = 25.4 ÷ PPI mm · 1 arc-minute: d = 1 ÷ (PPI × tan 1′)
Variables
| Symbol | Meaning | Unit |
|---|---|---|
wp | Screen width, in pixels | px |
hp | Screen height, in pixels | px |
dg | Screen diagonal | in |
PPI | Pixel density | ppi |
DP | Pixel pitch | mm |
MP | Total pixels | MP |
RD | Distance where single pixels stop being visible | cm |
SW | Screen width | cm |
Worked example
- Screen width, in pixels1920 px
- Screen height, in pixels1080 px
- Screen diagonal24 in
- Pixel density91.79 ppi
- Pixel pitch0.2767 mm
- Total pixels2.074 MP
- Distance where single pixels stop being visible95.1 cm
- Screen width53.1 cm
Limitations
- The calculation runs at full precision and only the display is rounded. If you copy an intermediate value and retype it, small differences can appear.
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.