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Screen Resolution, PPI & Aspect Ratio Calculator

Built by Kevin Glover · @gloverbuilds · Verified formula

Calculate pixels per inch (PPI), aspect ratio, and total pixel count from screen resolution and size.

📅 Updated April 2026 ✅ Formula verified 📖 4 min read 🆓 Free · No sign-up

In this article

Understanding PPI (Pixels Per Inch)
Common Resolutions

PPI

PPI = Wurzel(Breite² + Hoehe²) / Diagonale. iPhone: ~460 PPI. MacBook 14": 254. TV 65" 4K: 68. Ab ~300 PPI sind Pixel in Leseentfernung unsichtbar.

Formate

16:9: TV/Monitor Standard. 16:10: Produktivitaet. 21:9: Ultrawide. 4:3: alt.

⚡ CalcWolf Insight

The human eye can perceive approximately 300 PPI at 12 inches viewing distance — this is why Apple chose 326 PPI for the original Retina iPhone. At typical desktop viewing distances (24-30 inches), the equivalent is about 100-120 PPI. Buying a 5K monitor for a desktop you sit 3 feet from provides diminishing returns beyond bragging rights.

Frequently asked questions

Gutes PPI?▾

Smartphone: 300+. Notebook: 200+. Monitor: 100-120. TV: 60-80 reicht.

4K lohnenswert?▾

27" Monitor: ja. 55" TV bei 3 m Abstand: kaum sichtbarer Unterschied zu 1080p.

✓ Math logic verified against primary sources → See our verification process

Kevin Glover · @gloverbuilds

Founder, CalcWolf · GLVTS · Blickr

All formulas sourced from primary references — IRS publications, peer-reviewed research, and official standards. Results are tested against independent reference calculators before publishing. Rates and brackets updated when official sources change. Editorial policy →