How this calculator works
PPI divides the diagonal pixel count by the physical diagonal in inches. It assumes square pixels and a rectangular display. Display scaling changes apparent interface size but not the physical pixel density.
The formula
PPI = √(width² + height²) / diagonal inchesA quick example
A 1920 × 1080, 24-inch screen has approximately 91.787799 pixels per inch.
How to use this calculator
- Enter the labeled values, using a decimal point for fractions.
- Check the units and assumptions.
- Calculate, review the result and copy it if needed.
A few common questions
How is this result calculated?
PPI = √(width² + height²) / diagonal inches
What assumptions should I check?
PPI divides the diagonal pixel count by the physical diagonal in inches. It assumes square pixels and a rectangular display. Display scaling changes apparent interface size but not the physical pixel density.
Can I see a worked example?
A 1920 × 1080, 24-inch screen has approximately 91.787799 pixels per inch.