CPS KING

Mouse DPI test: measure your mouse's real DPI

Find your mouse's real DPI: move it across a bank card or a ruler, and the test counts what the mouse reports over that distance. Do a few sweeps and it shows the average and how steady it is. Raw movement is used, so Windows' and macOS' acceleration are left out.

Put the mouse at the start mark, then press Start measuring. The pointer hides until you press Esc.

Counts this sweep 0

Your DPI–
Sweeps0
95% interval–

    No download, no account: it runs in your browser, Chromebooks included.

    Bank card, 85.60 mm Start End Line up the same edge of the mouse each time
    Mark both ends of the card on your mouse pad, move the card out of the way, and slide the mouse from one mark to the other without turning or lifting it.

    How to measure

    1. Set the DPI you want to check in your mouse's software and leave it there.
    2. Lay a bank card (85.60 mm long) or a ruler on your mouse pad and mark both ends, for example with two strips of tape. Then move the card out of the way.
    3. Enter the distance, press Start measuring and put the left edge of the mouse on the first mark.
    4. Press Space, slide the mouse in a straight line until the same edge reaches the second mark, stop, and press Space again.
    5. Move the mouse back and repeat. Five sweeps give a steady average; Esc gives the pointer back.

    How exact is it?

    Your hand is the ruler's weak point. Lining the mouse up half a millimetre off on an 85.60 mm card changes the answer by about 0.6%, and that error stays in every sweep, so more sweeps do not remove it. A longer distance, such as 20 or 30 cm on a ruler, makes the same slip matter less. The 95% interval shows only how much your sweeps differ from each other.

    The test counts what the browser reports with raw movement switched on. Browsers are allowed to report movement in pixels rather than sensor counts, so treat the number as an estimate and compare it with the DPI set in your mouse's software. If the result changes when you change Windows' pointer speed, your browser is not giving raw movement.

    Which browsers can measure it

    Raw mouse movement works in Chrome and Edge 88 or newer on Windows, macOS 10.15.1 or newer and ChromeOS, Chrome 144 or newer on Android with a mouse plugged in, Firefox 152 or newer and Safari 18.4 or newer on a Mac. Chrome on Linux and browsers on iPhone and iPad can't do it, so the test explains that instead of giving a number.

    What to do with the number

    If it is close to the DPI your software shows, your setting is doing what it says. Multiply it by your in-game sensitivity in the eDPI calculator, or read the best DPI for gaming to choose a setting.

    Sources: W3C, Pointer Lock 2.0; MDN, requestPointerLock and its browser support and movementX; Wikipedia, ISO/IEC 7810 ID-1 card size; NIST, confidence limits for the mean.