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).