PPI Calculator – Pixels Per Inch for Any Screen

Calculate pixels per inch (PPI) for any display resolution and screen size.

About This Calculator

Calculate pixels per inch (PPI) for any display resolution and screen size. Use the calculator above for instant results.

Worked Examples

Example 1: 27" 2560×1440 (QHD/2K)

  • Diagonal pixels: 2935 | PPI: 108.8 | Good for desk use

Answer: 108.8 PPI

Example 2: 27" 3840×2160 (4K)

  • PPI: 163.2 | High density — excellent clarity

Answer: 163.2 PPI

Example 3: 5.5" phone 1080×1920

  • PPI: 400.5 | Very high density — true Retina

Answer: 400.5 PPI

Who Uses This Calculator?

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Monitor Buyers

Compare display sharpness.

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Phone Buyers

Evaluate screen sharpness.

📊
UX Designers

Design for different pixel densities.

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Hardware Reviewers

Quantify display quality.

Common Mistakes to Avoid

❌ PPI vs DPI

PPI = pixels per inch (screens). DPI = dots per inch (printers and mice). Not interchangeable.

❌ Retina threshold

Apple calls displays 'Retina' when PPI makes individual pixels imperceptible at typical viewing distance. For phones (~12"), ~300 PPI. For 27" monitors (~28"), ~100 PPI is sufficient.

Frequently Asked Questions

Good PPI for monitors?

21-27" at 1-3ft: 100-120 PPI is comfortable. 4K 27" (163 PPI) is excellent. Under 90 PPI may show pixelation.

Phone PPI?

Flagship phones: 400-570 PPI. Budget phones: 200-300 PPI. Above 300 PPI differences are barely visible.

PPI for print?

Print resolution is 300 DPI standard. Screen PPI and print DPI are different measurements — don't confuse them.