Move your mouse a measured distance along a ruler and the test works out its real DPI, averages several runs and compares them with the setting you chose.
Hold, move, release
Put the mouse at the 0 of a ruler with the pointer at the left of this box, hold the left button, move exactly 2 inches to the right and release.
How to measure your mouse's DPI
Lay a ruler on your desk or mouse pad and enter the distance you'll move: 2 inches or 5 cm suits most settings.
Press Lock pointer (or point at the left of the box to drag instead).
Line up the mouse's edge with 0, hold the left button, move it to the mark and release.
Repeat at least three times; the result is the average.
The formula
DPI = counts moved ÷ inches moved. In centimetres, divide by 2.54 first: 5 cm is 1.97 inches.
To check the buttons, wheel and polling rate, use the mouse test.
Everything runs in your browser; nothing is recorded or sent.
Frequently asked questions
How does the DPI test work?
DPI (or CPI) is how many counts the mouse reports per inch it moves. You move the mouse a measured distance and the test adds up the movement: 1,600 counts over 2 inches is 800 DPI, and 1,575 counts over 5 cm (1.97 inches) is 800 DPI.
Why is my result different from the DPI I set?
Sensors are rarely exact, so a few percent either way is normal, and the surface matters. Bigger differences usually come from pointer acceleration or a pointer speed other than the default, from not moving exactly the distance, or from moving at an angle. Do three runs or more and use the average.
What should I set before testing?
On Windows, turn off Enhance pointer precision (Settings → Bluetooth & devices → Mouse → Additional mouse settings → Pointer Options) and leave the pointer speed in the middle, 6 of 11. Turn off acceleration in the mouse's own software too. Locking the pointer asks the browser for raw movement, which skips the system's speed and acceleration where the browser supports it.
What is the difference between locking the pointer and dragging?
Locked, the pointer is hidden and movement is counted anywhere, so it can't stop at the edge of the screen. Dragging uses how far the pointer moved on screen, which depends on the system's pointer speed and stops at the screen's edge, so use a shorter distance.
Does it work on a touch screen or touchpad?
No: it needs a mouse moved along a ruler. A touchpad has no ruler distance to measure, and phones have no pointer to lock.
