What this tool does
Calculates PPI from screen resolution (width × height in pixels) and physical diagonal size in inches.
Converter and calculator
Screen DPI Calculator
Calculate the PPI (pixels per inch) of any screen given its resolution and diagonal size. Useful for display comparisons and design decisions.
Complete guide
How to use Screen DPI Calculator
Unit converters guide for screen dpi calculator users.
PPI (pixels per inch) determines how sharp a screen appears. Higher PPI = sharper text and images. Apple's Retina displays are 220+ PPI. Typical HD monitors are 90–110 PPI. This calculator lets you find the PPI of any display given its pixel resolution and physical diagonal size.
How to use it
Enter width and height in pixels and the diagonal screen size in inches. PPI and dot pitch are calculated instantly.
PPI benchmarks
Under 100 PPI: visible pixels. 100–150 PPI: typical desktop. 150–220 PPI: good laptop. 220+ PPI: Retina/HiDPI — indistinguishable pixels at normal distance.
Quick checklist
- Use the actual screen resolution, not the OS scaling resolution.
- Diagonal size is usually listed in specs and on the box.
- Formula: PPI = √(width² + height²) ÷ diagonal.
- HiDPI starts at ~220 PPI for normal desktop viewing distance (~60cm).
Answers
Screen DPI Calculator FAQs
What is a good PPI for a monitor?
For desktop monitors at ~60cm viewing distance: 90–110 PPI is standard, 150+ is sharp, 220+ is Retina quality.
What is the formula for PPI?
PPI = √(horizontal_pixels² + vertical_pixels²) ÷ diagonal_inches.
What is dot pitch?
Dot pitch is the physical distance between pixels in mm. It is the inverse of PPI. Lower dot pitch = higher density = sharper image.
How do I find my screen's resolution?
Windows: Settings → Display → Resolution. macOS: System Settings → Displays. This shows logical resolution — the actual panel may differ with scaling.