How this calculator works
Enter the values for first value, second value and review the units before calculating.
Formula / method
PPI = √(horizontal² + vertical²) ÷ diagonal
Worked example
A 1920×1080 display measuring 24 inches diagonally is about 91.8 PPI.
Assumptions and limitations
Pixel dimensions are native resolution and diagonal size is measured in inches.
Displayed scaling, viewing distance and subpixel layout are not included.