PPI Calculator
PPI calculator works out Pixel density and Screen width from Horizontal resolution, Vertical resolution and Screen diagonal. The default figures on this page give pixel density of 91.787799 ppi; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
4 steps
- Diagonal in pixels = sqrt(1920^2 + 1080^2) = 2202.9072 px
- Pixel density = 2202.9072 / 24 in = 91.7878 ppi
- Panel measures 20.918 x 11.766 inches (16:9)
- Dot pitch = 25.4 / 91.788 = 0.2767 mm
Its 5 worked examples are re-run on every release, last on 15 September 2026. What changed
Sources and references
2 sources
What the ppi calculator calculates
Computes pixel density, physical width and height, and aspect ratio from a screen resolution and diagonal measurement.
How to use this ppi calculator
Enter Horizontal resolution, Vertical resolution, Screen diagonal and Viewing distance. Pixel density updates as you type, and “Use a worked example” loads checked figures you can adjust. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Pixel density, Screen width and Screen height.
The method follows Pixel density: ppi = sqrt(width_px^2 + height_px^2) / diagonal_inches and IEC 80000-13, quantities and units for information science and technology.
Research R1888-GT-1: 1920x1080 on a 24 inch panel example
With Horizontal resolution: 1920, Vertical resolution: 1080, Screen diagonal: 24, the calculator returns Pixel density: 91.7877988. This example is checked against an independent source in the test suite.
What you can compare
Change one input at a time to see how it affects Pixel density, Screen width and Screen height. The inputs you can vary are Horizontal resolution, Vertical resolution, Screen diagonal and Viewing distance.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
See something wrong? Report a problem with this calculator
Frequently asked questions
What information do I need for the ppi calculator?
You need Horizontal resolution, Vertical resolution, Screen diagonal and Viewing distance. The page opens with default figures that give pixel density of 91.787799 ppi, so you can see the scale before entering your own.
What does this ppi calculator show?
It shows Pixel density, Screen width, Screen height, Aspect ratio, Screen area, Total pixels, Dot pitch and Pixels per degree at the viewing distance, with the working and any warnings for your entries.
Can I check how the ppi calculator result was calculated?
Yes. The “How this is worked out” section shows the calculation steps, and the sources section identifies the references used for the method.