AI & Computing

PPI Calculator (Pixel Density of a Screen)

Enter resolution and diagonal size to get pixels per inch.

By TheCalcTools Updated Formula checked and tested

Your numbers

Your results

Pixel density (PPI)
Pixel density (PPI)
—
Dot pitch (mm)
—
Megapixels
—
Aspect ratio
—
Distance where pixels blend (20/20 vision, inches)
—

PPI Calculator (Pixel Density of a Screen) by TheCalcTools

How the PPI Calculator (Pixel Density of a Screen) works

Pixel density is the diagonal resolution in pixels divided by the diagonal size in inches. Higher PPI looks sharper at the same distance.

At about one arc-minute per pixel (typical 20/20 vision) individual pixels stop being visible; the last result estimates that viewing distance.

The formula

PPI = √(w² + h²) ÷ diagonal

Worked example

Using the default values shown in the calculator:

Horizontal pixels2560
Vertical pixels1440
Diagonal (inches)27
  1. √(2560² + 1440²) = 2,937 pixels ÷ 27 in = 108.8 PPI.

Result:

Pixel density (PPI)108.8
Dot pitch (mm)0.2335
Megapixels3.69
Aspect ratio1.778
Distance where pixels blend (20/20 vision, inches)31.6

Frequently asked questions

Is higher PPI always better?

Only up to the point your eyes can resolve at your viewing distance. Beyond that it costs battery and GPU power with little visible gain.

Sources and further reading

Screen Size and PPI CalculatorTurn a diagonal measurement into actual width and height Aspect Ratio CalculatorKeep proportions when scaling a photo, video or design Image File Size Calculator (Uncompressed and Megapixels)Enter the resolution and colour depth to get the image's memory size Video File Size and Bitrate CalculatorEnter bitrate and duration to get the file size, or a target size to get the bitrate

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This calculator gives estimates for information only. Check important results independently before you rely on them. See our disclaimer.