Screen PPI Calculator
Enter your screen's resolution (width × height) and diagonal size to calculate pixels per inch (PPI) and dot pitch — a measure of screen sharpness.
Screen PPI Calculator
Pixels per inch and dot pitch
PPI = √(width² + height²) ÷ diagonal. Dot pitch = 25.4 ÷ PPI (mm).
What Is PPI?
Pixels Per Inch (PPI) measures screen sharpness — how many pixels fit into one inch of screen. Higher PPI = sharper, more detailed image.
PPI = √(width² + height²) ÷ diagonal inches Dot pitch (mm) = 25.4 ÷ PPI
**Typical PPI ranges**: - Smartphone: 300–500+ PPI - Laptop: 100–150 PPI - Desktop monitor: 90–110 PPI - 4K TV (55"): ~80 PPI
**Retina**: Apple's term for screens where the human eye can't resolve individual pixels at normal viewing distance (~300+ PPI for phones held close).
- Higher PPI = sharper screen
- Phones 300–500+ PPI, monitors ~100 PPI
- Dot pitch = 25.4 ÷ PPI (mm)
- Retina ≈ pixel density beyond eye resolution
Worked Example
Example: 1920 × 1080 resolution, 24-inch diagonal.
- Diagonal pixels = √(1920² + 1080²) = √(3,686,400 + 1,166,400) = √4,852,800 ≈ 2202.9 - PPI = 2202.9 ÷ 24 ≈ 91.8 PPI - Dot pitch = 25.4 ÷ 91.8 ≈ 0.28 mm - Total pixels = 1920 × 1080 = 2,073,600 (~2.1 MP)
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Open calculator →Frequently Asked Questions
Is higher PPI always better?
Generally yes for sharpness, but beyond ~300 PPI the human eye can't tell the difference at normal viewing distance. Higher PPI also costs more and uses more GPU/battery.
PPI vs. DPI — what's the difference?
PPI is for screens (pixels per inch). DPI is for printing (dots per inch). They're related but measure different things.
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