How the DPI analyzer works
The analyzer measures your sensor’s real DPI, also called CPI (counts per inch).
- Pick a real distance: 4 inches by default, or 10 cm.
- Put a ruler on your desk, along your mouse pad.
- Click Start. The pointer is locked and hidden (Pointer Lock). Press Esc to exit.
- Hold the left button, move the mouse in a straight line over exactly the chosen distance, and release.
- Repeat for 3 measures.
The math is simple: DPI = counts received / distance in inches (1 inch = 2.54 cm). After 3 measures the tool shows the average and the spread between them. Above 5 % spread, redo the measures more carefully. It also shows the nearest standard setting (400, 800, 1000, 1200, 1600, 2000, 2400, 3200 or 6400) and the gap in %.
Raw input and browsers
On Chrome and Edge, the lock asks for unadjusted movement, which ignores Windows pointer speed and acceleration. The tool then says “raw input” and the result is the sensor’s own.
On Firefox and Safari, movement goes through the OS. Set Windows pointer speed to step 6 of 11 and turn off Enhance pointer precision, or the result will be wrong. On macOS, acceleration is always on outside raw input.
Windows pointer speed
The tool has a Windows step selector and shows your effective desktop DPI = DPI x multiplier.
| Step | Multiplier | Step | Multiplier |
|---|---|---|---|
| 1 | 0.03125 | 7 | 1.5 |
| 2 | 0.0625 | 8 | 2 |
| 3 | 0.25 | 9 | 2.5 |
| 4 | 0.5 | 10 | 3 |
| 5 | 0.75 | 11 | 3.5 |
| 6 | 1 |
Example: 800 DPI at step 8 gives 1600 effective DPI on the desktop. Games with raw input ignore this setting.
Limits of a manual measure
- Your ruler and your hand: 1 mm of error over 10 cm is 1 %. Start and stop exactly on the marks.
- Display scaling (125 %, 150 %) can skew the measure in some browsers. If your result is off by about that factor, that is the cause.
- Surface: the sensor must track the pad. Lift-off distance does not matter, but do not lift the mouse during a measure.
Next step
With the DPI confirmed, check how often your mouse reports with the polling rate test. To test the buttons, use the mouse test.
Frequently asked questions
How do I check my mouse DPI?
Put a ruler on your desk, click Start, hold the left button, move the mouse in a straight line over exactly 4 inches and release. The tool divides the counts it received by the distance in inches. Repeat 3 times.
Why is my DPI different from the advertised value?
Sensors are rarely exact. A gap of 2 to 10 % from the advertised DPI is common. The tool shows the nearest standard setting and the gap in %.
Does Windows pointer speed change my DPI?
Not the sensor's DPI, but the cursor's effective DPI on the desktop. At step 8 of 11 the cursor moves twice as far, so 800 DPI acts like 1600. Games that use raw input, like CS2, Valorant and most FPS, ignore this slider.
Should I turn off Enhance pointer precision?
Yes, for gaming and for this test in Firefox or Safari. It is mouse acceleration, so the cursor distance depends on how fast you move, which is bad for muscle memory.
What is eDPI?
eDPI is your DPI multiplied by your in-game sensitivity. It lets you compare sensitivity between players who use different DPI settings.
Updated October 26, 2026