What is the Pixel Density (PPI) Calculator?
Measure pixel density in pixels per inch for a phone, monitor, television or other rectangular display.
Pixel pitch is the reciprocal of PPI converted from inches to millimeters.
Formula and calculation method
PPI = √(horizontal pixels² + vertical pixels²) ÷ diagonal inches.
The calculation runs locally in your browser and uses only the values entered on this page.
Important limitations
Technology estimates simplify real systems. Hardware, software, network conditions, measurement conventions and manufacturer behavior can change actual results.
Planning scope: Use the result as an estimate and confirm critical sizing or configuration with current product documentation.
Pixel Density (PPI) Calculator FAQs
PPI describes display pixels; DPI commonly describes print dots.
Viewing distance, eyesight, scaling and subpixel layout also affect perceived sharpness.
Convert the measured diagonal to inches before entry; 1 inch equals 2.54 cm.
No. Results are educational estimates based only on the values and simplifying assumptions entered.
Yes. A displayed result is hidden as soon as an input changes so an old answer is not mistaken for a current calculation.
Yes. The form, colorful result panel and calculation steps are responsive for phones, tablets and desktops.
Sources and methodology
Official source links support terminology and measurement context. The arithmetic runs locally in your browser.