DPI Analyzer

A DPI analyzer measures how many counts your mouse sensor sends for every inch it travels. To use the one above, lay a ruler on your mouse pad, enter the distance you will move, hold the left button inside the box, slide the mouse exactly that far to the right, and release. The large number 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. Sensors drift a few percent from the nominal value, a DPI button can be on a different stage than you think, and a cheap mouse may not match its listing at all. A measured value lets you copy a sensitivity between two mice, confirm which stage is active, and spot a sensor that is far off its setting.

How to use the DPI analyzer

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 the 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, cm or mm under Unit. The default is 2 inches; longer is more accurate.
3. No ruler? Press one of the No ruler? presets. A4 long edge sets 29.7 cm, US Letter long edge sets 11 in, and Bank card width sets 8.56 cm. Slide along the edge of that object instead.
4. If you know what the mouse is set to, enter it in DPI setting (optional) so the panel can show how far off it is.
5. Hold the left button inside the box. The cursor disappears and a live count starts.
6. Slide the mouse to the right along the ruler for exactly the distance you entered, then release the button.
7. Repeat a few times. The panel keeps your last ten 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 and stages.

How to read the results

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% and the nearest stage is 800. Centimetres and millimetres are converted before the division: move 10 cm, which is 3.94 inches, collect 3,150 counts, and the result is 800 DPI.

What DPI means for a mouse

DPI stands for dots per inch. For a mouse it is the number of position updates, or counts, the sensor sends for each inch of travel. At 800 DPI, moving the mouse one inch sends 800 counts, and with no scaling anywhere in the chain the cursor moves 800 pixels. At 1600 DPI the same inch sends 1,600 counts and the cursor goes twice as far.

DPI versus CPI

Sensor makers call the same figure CPI, counts per inch, because the sensor reports counts rather than printing dots. Mouse brands and players mostly say DPI. The two numbers are identical, and this DPI checker measures exactly that count rate. If a spec sheet lists 26,000 CPI and the box says 26,000 DPI, they mean the same thing.

DPI is not sensitivity

DPI is set on the mouse. Sensitivity is set in each game and multiplies the counts after they arrive. The value you actually feel is the product of the two, called eDPI, and the distance your hand travels for one full turn is cm/360. Two players with 400 DPI at 2.0 sensitivity and 800 DPI at 1.0 sensitivity have the same eDPI of 800 and turn the same amount per inch. The DPI vs sensitivity guide covers which one to change and why, and the eDPI calculator turns your numbers into something you can compare with other players.

Why the measured DPI differs from the setting

Four things explain almost every gap you will see.

• Sensor tolerance. Optical sensors are calibrated at the factory to a nominal value and usually land within 2 to 5 percent of it. A mouse that measures 780 or 830 when set to 800 is normal.
• Your swipe. Starting late, stopping early or rotating the mouse costs counts. On a 2 inch run, 2 mm of error is 4 percent of the result. Use 5 inches or an A4 sheet and the same error drops below 1 percent.
• Pointer acceleration. Windows Enhance pointer precision and macOS pointer acceleration change the cursor's speed with how fast you move. This analyzer asks the browser for unadjusted movement, which bypasses acceleration in Chrome and Edge. If your browser cannot provide it, the panel says so, and you should turn acceleration off in the system settings before measuring.
• The wrong stage. Most gaming mice store four or five DPI stages and cycle through them with a button that is easy to press by accident. A measured 1,600 on a mouse you believe is at 800 is not a faulty sensor; it is the next stage. Use the stage slots to map the button.

How to find your current DPI setting

If you want the number the mouse is set to rather than the number it delivers, there are two places to look before measuring. The manufacturer's software, such as Logitech G HUB, Razer Synapse or SteelSeries GG, shows every stored stage and highlights the active one. A mouse without software has its fixed DPI or its stage list on the product page or in the manual. Windows and macOS have no DPI setting anywhere; the pointer speed slider is a separate multiplier. The full walkthrough for each platform and brand is in how to check mouse DPI, and when the setting is not what you want, how to change mouse DPI covers the button, the software and what to do without either.

When to measure your DPI

• Switching mice. Measure the old mouse, measure the new one, and use the DPI calculator to set an in-game sensitivity that keeps the same cm/360 on the new sensor.
• Second-hand or unbranded mice. A listing that says 3200 DPI is a claim. One swipe tells you whether it is true and which stage the button is on.
• A game suddenly feels different. Before touching in-game settings, confirm the DPI stage did not change. An accidental press of the DPI button is the most common cause.
• Copying a pro's settings. Pro settings are listed as DPI plus sensitivity. Matching only the sensitivity while your DPI is on a different stage gives you a different feel entirely. The mouse sensitivity converter handles the conversion between games once your DPI is confirmed.
• Checking a warranty claim. A sensor that measures 30 percent off its setting on every stage, with careful swipes and acceleration off, is a fault worth reporting.

Privacy and requirements

The analyzer reads pointer movement events in your browser and does the division locally. Nothing about your input is sent to a server, and there is no account or download. It needs a real mouse: a finger on a touch screen has no DPI to measure, so on phones and tablets the panel shows a notice instead of a wrong number. It works in any current desktop browser on Windows, macOS, Linux and ChromeOS; Chrome and Edge give the cleanest readings because they expose raw sensor input.