About the PPI Calculator
A PPI (pixels per inch) calculator measures how sharp a screen is — how many pixels fit into each inch. Enter the horizontal and vertical resolution and the diagonal screen size in inches to get the PPI, the dot pitch (distance between pixels) and the total megapixels. For screens, PPI and DPI mean the same thing.
How PPI Calculator works
PPI = √(width² + height²) ÷ diagonal size (inches).
Example: a 1920 × 1080 display on a 24-inch screen → √(1920² + 1080²) ÷ 24 ≈ 91.8 PPI. Dot pitch = 25.4 ÷ PPI mm.
Common uses
- Compare the sharpness of two displays
- Check if a screen qualifies as 'Retina' / high-DPI
- Find dot pitch for monitor specs
- Work out megapixels of a display
Frequently asked questions
What is PPI?
Pixels per inch — the number of pixels in each inch of a display. Higher PPI means a sharper image.
Is PPI the same as DPI?
For screens, yes, the terms are used interchangeably. DPI (dots per inch) is technically a print term.
What is a good PPI?
Desktop monitors are often 90–110 PPI; phones and 'Retina' displays are 300+ PPI, where individual pixels are hard to see.