DPI Test

A DPI test measures how many counts your mouse sensor sends for every inch it travels. To run the test above, enter a distance, hold the left button inside the box, slide the mouse exactly that far to the right along a ruler, and release: the reading is your real DPI.

That number is worth checking because the DPI printed on the box, shown in the software, or selected with the DPI button is a target, not a guarantee. A measured value lets you copy a sensitivity between two mice, confirm which DPI stage is active, and spot a sensor that is far off its setting.

How to use the DPI test

You need a ruler, a tape measure, or any object with a known length, plus enough desk space to slide the mouse in a straight line.

1. Lay the ruler flat on your mouse pad, parallel to the bottom edge of your keyboard, and rest one side of the mouse against it.
2. Type the length you plan to move into Distance to move and pick in or cm under Unit. The default is 2 inches.
3. If you know what the mouse is set to, enter it in DPI setting (optional).
4. Hold the left button inside the box. The cursor disappears and a live count starts.
5. Slide the mouse to the right along the ruler for exactly the distance you entered, then release the button.
6. Repeat a few times. The panel keeps your last five runs and averages them.

Only horizontal movement is counted, so keep the mouse square to the ruler. If the mouse drifts diagonally or rotates in your hand, part of the motion goes into the vertical axis and the reading comes out low.

Press Esc at any time to cancel a run. Reset clears the saved runs so you can start over after changing the DPI stage.

How to read the results

The panel shows three numbers under the box.

A worked example: you set the distance to 2 inches and the counter stops at 1,648. The tool divides 1,648 by 2 and reports 824 DPI. If you entered 800 as the setting, Off from setting reads +3.0%.

Centimetres are converted before the division. Move 10 cm, which is 3.94 inches, and collect 3,150 counts, and the result is 800 DPI.

How to check your mouse DPI: three methods

People asking how to check mouse DPI usually want one of two things: the number the mouse is set to, or the number it actually delivers. These three methods cover both.

1. Check the manufacturer's software

If your mouse comes with a companion app, open it and look for a DPI, sensitivity, or performance tab. It shows every DPI stage stored on the mouse and which one is active. This is the fastest way to see the setting, and the only way to change it on most models.

2. Look up the model's specifications

A basic office mouse usually has no software and one fixed DPI. Search for the model number printed on the underside and read the specification sheet. Fixed values around 800 to 1600 DPI are common for office mice, but it depends on the model.

Mice with a DPI button cycle through preset stages, and many signal the active stage with an LED colour. The manual tells you which colour maps to which value. Without it, you are guessing, which is where method three comes in.

3. Measure it with this DPI checker

Measuring works on any mouse, including unbranded ones, and it reports what the sensor really does instead of what a label claims. Run the test at each DPI stage and write the results down. You end up with a map of your DPI button even if the manual is long gone.

There is no DPI setting to find in Windows or macOS themselves. The pointer speed slider in the operating system scales the counts after they arrive; it does not change or reveal the sensor's DPI.

DPI vs CPI: is there a difference?

No. DPI stands for dots per inch, a term borrowed from printing, and CPI stands for counts per inch. A mouse sensor reports counts of movement, so CPI is the more accurate name, and a few manufacturers use it in their software.

Both labels refer to the same number. A mouse at 800 CPI and a mouse at 800 DPI send 800 counts for each inch of travel.

Why your measured DPI does not match the setting

A result that lands a few percent off is normal. Several things contribute, and only one of them is the mouse.

• Sensor tolerance. Real sensors deviate from their nominal value, and the amount varies by model and even between two units of the same model. Seeing 780 or 830 on an 800 DPI setting is ordinary.
• Distance error. On a 2 inch swipe, stopping 2 mm early changes the result by about 4 percent. Over 10 inches the same 2 mm slip is under 1 percent.
• Angle. Because only the horizontal axis is counted, a mouse held at a slight angle to the ruler reads low.
• Surface and lift. If the mouse lifts or skips on a glossy or uneven surface, counts are lost.
• Pointer acceleration. If the browser cannot provide raw input, the operating system's processing is baked into the counts. More on that below.

The Off from setting figure is highlighted once the gap passes 10 percent. A gap that large and that consistent rarely comes from tolerance alone. Check that the DPI stage you think is active really is, and that the profile in your mouse software was saved to the device.

Why pointer acceleration ruins a DPI measurement

Pointer acceleration makes the cursor travel farther when you move the mouse quickly than when you move it slowly over the same physical distance. Windows calls it "Enhance pointer precision", and macOS applies its own acceleration curve by default. With acceleration in the path, the same 2 inch swipe yields different counts depending on your hand speed, so no single DPI figure comes out.

The test avoids this where it can. While you hold the button it locks the pointer and asks the browser for unadjusted movement, which is the raw count stream from the mouse before the operating system touches it. When that works, the note under the panel says the reading uses raw sensor counts, and your system pointer settings have no effect on the result.

Not every browser and platform supports raw input. When it is unavailable, the note changes to tell you so, and you should switch acceleration off before measuring:

• Windows: open Mouse settings, go to Additional mouse settings, open the Pointer Options tab, and untick "Enhance pointer precision". Leave the pointer speed slider at its default middle position.
• macOS: open System Settings, choose Mouse, and turn off pointer acceleration if your version offers the toggle. If it does not, run the test in a browser that supports raw input.

A quick way to tell whether acceleration is affecting you: do one slow swipe and one fast swipe over the same distance. If the two results differ by much more than your usual run-to-run spread, something is scaling the input.

Tips for a more accurate reading

• Go longer. Use the full width of your mouse pad. Ten inches or 25 cm shrinks the effect of a sloppy start or stop.
• Use a hard edge. Press the side of the mouse against the ruler so it cannot rotate.
• Mark start and stop. Line up the same edge of the mouse with the ruler marks at both ends, not the front at one end and the back at the other.
• Move at a steady, moderate speed. Very fast swipes can make some sensors skip, and a jerky stop overshoots the mark.
• Take five runs. Throw out any run where you know you slipped by pressing Reset and starting again, then read the average.
• Skip very short moves. Tiny movements are ignored, and short distances magnify every error.

What to do with your DPI number

Once you have a measured value, you can put it to work.

Match sensitivity across mice. Two mice both set to 800 DPI can feel different if one really delivers 770 and the other 830. Measure both and nudge the DPI on one of them until the readings agree. Your muscle memory carries over.

Work out your eDPI. Effective DPI is DPI multiplied by in-game sensitivity, and it is how players compare settings. With a measured 824 DPI and a sensitivity of 0.5, your eDPI is 412. Using the measured figure instead of the nominal one keeps the comparison honest.

Identify DPI stages. Press the DPI button, run the test, and note the result. Repeat until the values loop.

Decide whether a sensor is faulty. Readings that swing wildly between careful runs point to a dirty lens, an unsuitable surface, or a failing sensor. Clean the sensor opening, try a plain cloth mouse pad, and test again before you blame the hardware.

Related tests

DPI is one part of how a mouse tracks. The polling rate test shows how often the mouse reports its position, which affects how smooth that tracking feels. After changing DPI, a round of the mouse accuracy test tells you whether the new setting helps or hurts your aim, and the CPS test covers click speed.

To check the buttons and scroll wheel as well, run the full mouse test on the home page.