Mouse DPI Test
Estimate your effective mouse sensitivity in pixels per inch using an on-screen calibration ruler and a physical measurement.
Test interface
Your browser may ask for permission after you press Start.Match the on-screen ruler to 10 cm on a real ruler, then measure a straight physical movement.
Start at one side and move the mouse in a straight line
How to use this tool
- Place a real ruler or tape measure against the on-screen ruler and adjust it until 10 cm matches.
- Click Start measurement, then move the mouse steadily along 10 cm of the real ruler.
- Click Stop and read the effective pixels-per-inch estimate.
- Repeat two or three times and compare the results.
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Technical explanation
The calibration step converts CSS pixels to physical centimetres. During measurement the page sums the pointer travel reported by the browser and divides it by the physical distance you moved the mouse. The result is effective screen pixels per inch, which combines sensor DPI, operating-system pointer speed, and acceleration.
Browsers do not expose raw mouse counts or the hardware DPI value. OS acceleration, pointer acceleration curves, and rounding make this an estimate. To estimate the sensor DPI, divide the result by your operating-system sensitivity multiplier if you know it.
Troubleshooting
The on-screen ruler cannot match 10 cm
Browser zoom and display scaling change CSS pixel size. Set zoom to 100 percent and adjust the ruler again.
The estimate is very different from the mouse specification
Operating-system pointer speed and acceleration have a large effect. This tool reports effective sensitivity, not the sensor DPI.
Results are inconsistent
Move at a steady speed, keep the mouse straight, and avoid lifting it during the measurement.
The pointer hits the screen edge
Start with the pointer near one side and use a shorter physical distance, or lower the system sensitivity.
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Frequently asked questions
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