Screen Pixels Per Inch (PPI) Calculator
Calculate a screen's pixel density (PPI) from its resolution and diagonal size in inches.
Your results
Calculation breakdown
- Diagonal pixels
- √(width² + height²)
- PPI
- diagonal pixels ÷ diagonal inches
Worked example
A 24-inch 1920x1080 monitor has a diagonal of about 2203 pixels, giving roughly 92 PPI.
Assumptions
- Screen size must be entered in inches, the standard Australian retail convention for displays.
- Assumes a flat, rectangular screen.
How this calculator works
Find the pixel density of a monitor, TV or phone screen from its resolution width, height and diagonal size in inches. Higher PPI generally means a sharper-looking image at normal viewing distance.
Frequently asked questions
What counts as a high PPI?
Around 300 PPI or more is often called 'Retina-class' for close-up devices like phones; desktop monitors are typically sharp from about 110 PPI up.
Does PPI alone determine sharpness?
No, viewing distance matters too — a lower-PPI TV viewed from across a room can look just as sharp as a high-PPI phone held close.
Can I use centimetres instead of inches?
Screen sizes are conventionally quoted in inches in Australia and worldwide, so convert centimetres to inches first (divide by 2.54).
Editorial review and responsibility
Reviewed by the CalcAussie editorial team on 21 September 2026. Review scope: Method, Australian terminology, material assumptions, source links and user-facing limitations.
Calculator results remain estimates based on the figures entered. Check material decisions against current official information and report a suspected error so it can be reproduced and corrected.