Pixel Density (PPI) Calculator
Calculate screen pixel density and approximate physical width and height from resolution and diagonal size.
Your result
Review your calculated values below.
Ready when you are.
Choose Calculate to see your result.
How to use this calculator
- Enter your values in the labeled fields, keeping the displayed units.
- Choose Calculate or press Enter in a single-line field.
- Review the result and the assumptions below before using it.
Formula and method
PPI = √(width pixels² + height pixels²) / diagonal inches. Physical width = horizontal pixels / PPI.
Worked example
A 24-inch 1920 × 1080 display has approximately 91.79 pixels per inch.
What the result assumes
Assumes square pixels and a rectangular active display area. Nominal diagonal measurements can be rounded by manufacturers.
Common question
Is PPI the same as printer DPI?
PPI measures image or screen pixels per inch. DPI describes printer dots and is not necessarily one dot per pixel.