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PPI Calculator
Pixels per inch (PPI) tells you how sharp a screen is. Enter the resolution and the diagonal size to get the pixel density, the dot pitch between pixels and the total pixel count.
- Dot pitch
- 0.2767 mm
- Diagonal in pixels
- 2,203 px
- Total pixels
- 2.07 MP
Saved setups
Save a set of inputs you reuse — your usual rate, your loan, your room sizes — and load it back in one tap.
Your recent calculations
Results you calculate here are kept on this device so you can come back to them.
Formula
How to use it
- Enter the horizontal and vertical resolution in pixels.
- Enter the diagonal screen size; switch the unit to cm if needed.
- Compare the PPI with other screens you are considering.
Worked examples
A 24-inch 1920 × 1080 monitor: 2,203 diagonal pixels ÷ 24 in
- Pixel density
- 91.79 PPI
- Dot pitch
- 0.2767 mm
- Diagonal in pixels
- 2,203 px
- Total pixels
- 2.07 MP
A 27-inch 4K (3840 × 2160) monitor
- Pixel density
- 163.18 PPI
- Dot pitch
- 0.1557 mm
- Total pixels
- 8.29 MP
What the numbers mean in practice
A 24-inch 1080p monitor is about 92 PPI, a 27-inch 1440p about 109 PPI, and a 27-inch 4K about 163 PPI. Phones run far higher, often 400 PPI or more, because they are held much closer.
Density and viewing distance
Whether you can see individual pixels depends on how far away you sit as well as on PPI. A 65-inch 4K TV is only 68 PPI yet looks sharp from the sofa, while the same density on a desk monitor would look coarse.
PPI and DPI
PPI describes pixels on a screen or in an image. DPI strictly means ink dots from a printer, though the two terms are often used interchangeably.
Questions people ask
What is the PPI of a 27-inch 4K monitor?
About 163 PPI: √(3840² + 2160²) = 4,406 pixels along the diagonal, divided by 27 inches.
What is the PPI of a 24-inch 1080p monitor?
About 92 PPI, with a dot pitch of 0.277 mm.
Is a higher PPI always better?
Sharper, yes, but past the point where you can no longer see pixels at your viewing distance the gain is invisible, while the graphics hardware has to work harder.