Screen Size Calculator

PPI = √(Width² + Height²) ÷ Diagonal. Higher PPI means sharper text and images.

What this calculator does

Retina threshold: ~220 PPI at arm's length. Most phones exceed 400 PPI.

Frequently asked questions

What is a good PPI for a monitor?

109 PPI (24" 1080p) is standard. 163 PPI (27" 4K) is excellent. Above 200 PPI is retina-quality.