How to measure your mouse DPI
- Pick a distance. A bank or ID card is 3.37 inches (85.6 mm) wide, so you can use one if you don't have a ruler. Longer distances, like 10 cm or 4 inches, give a more precise result.
- Line up the mouse. Put the ruler or card flat on your mouse pad and align the left edge of the mouse with the start mark.
- Press Start, slide, click. Move the mouse straight to the right until its left edge reaches the end mark, then click once or press Space. Don't lift the mouse on the way.
- Repeat two more times. The DPI analyzer averages the runs and shows how close they were. A spread of ±3% or less means a clean measurement.
The cursor disappears while you measure: the page locks it so it can't stop at the edge of the screen. Press Esc at any time to cancel.
Raw counts vs. system pointer
Under the button, the tool tells you what it could read. Raw sensor counts means the browser supports unadjusted mouse input (current Chrome and Edge on Windows do), so Windows pointer speed and acceleration don't affect the result. If it says system pointer, the movement has passed through your operating system first, so check these settings before you trust the number:
- Windows: Settings › Bluetooth & devices › Mouse › Additional mouse settings › Pointer Options. Untick "Enhance pointer precision" and leave the speed slider at the middle notch (6 of 11). Any other notch scales the result.
- macOS: macOS always applies acceleration to the pointer, so a result in system pointer mode is only a rough estimate. Run the test in Chrome or Edge on Windows for an accurate reading.
Why your DPI isn't exactly what the box says
A mouse DPI test almost never lands on the exact advertised number. Sensor tolerance of about 5–10% is normal, and the surface, the mouse feet and the lift-off distance all move the result a little. What the result is useful for:
| Your result | What it means |
|---|---|
| Within 10% of the setting | Normal. The mouse does what it promises. |
| About double or half | Pointer speed or display scaling is changing the reading, or the mouse is on a different DPI step than you think. |
| Changes a lot between runs | Uneven movement, a dirty sensor or a glossy or glass surface. Clean the sensor and use a cloth mouse pad. |
| You don't know the setting | Use "nearest setting" as a guide, then press the DPI button (usually under the wheel) and test again to find each step. |
DPI, sensitivity and eDPI
DPI (or CPI, counts per inch) is how many steps the sensor reports for each inch you move. Higher DPI isn't automatically better: it moves the cursor further, and many players lower it again with in-game sensitivity. To compare settings, multiply DPI by sensitivity to get eDPI with the calculator above. For desktop work, 800–1600 DPI suits most screens up to 1440p; on a 4K screen many people go higher so they don't have to lift the mouse.
If your mouse misbehaves in other ways, the mouse test checks every button, double clicks and the scroll wheel, and the keyboard test does the same for your keys.
How we tested this tool
We checked the calculation in Chrome by sending mouse-movement events with known totals: 2,696 counts over 3.37 inches came out as 800 DPI, 1,575 counts over 10 cm as 400 DPI, and three runs of 1,580, 1,600 and 1,620 DPI averaged to 1,600 with a ±1% spread. A run with more than 15% sideways movement was flagged and left out of the average, Esc cancelled a run and the eDPI calculator multiplied correctly. We haven't measured physical mice against a lab reference yet, so treat the result as a close estimate.
Frequently asked questions
Why is my measured DPI different from the number on the box?
Mouse sensors are rarely exact. A difference of up to about 5 to 10 percent is common, and it changes with the surface and the lift-off height. If you get a value close to double or half the setting, Windows pointer speed or display scaling is involved; see the settings section on this page.
How do I check my mouse DPI without software?
Use this mouse DPI test: put a ruler or a bank card next to the mouse, press Start, move the mouse exactly that distance and click. The page divides the counts the mouse reported by the distance in inches. Repeat three times and use the average.
Does Enhance pointer precision change the DPI result?
It changes the result only when the browser can't read raw input. When the page shows 'raw sensor counts', acceleration and pointer speed are bypassed. Otherwise turn off Enhance pointer precision and leave pointer speed at the middle notch (6 of 11) for a 1:1 reading.
What DPI should I use for gaming?
Most competitive shooter players use 400 to 1600 DPI and set the rest with in-game sensitivity. What matters for aim is eDPI (DPI times sensitivity) and how far you move the mouse for a full turn, not the DPI number on its own.
What is eDPI?
Effective DPI is your mouse DPI multiplied by your in-game sensitivity. 800 DPI at sensitivity 0.5 gives an eDPI of 400, the same feel as 400 DPI at sensitivity 1 in the same game. Use it to compare settings between players of the same game.