Mouse DPI Calculator

What mouse DPI means, and why CPI is the same number

DPI stands for dots per inch, and on a mouse it means the number of counts the sensor reports for one inch of travel. A mouse set to 800 DPI sends 800 counts when you move it one inch across the pad. Each count is therefore 1/800 of an inch, or 0.03175 mm, which is the number that matters for aiming.

CPI, for counts per inch, is the accurate term, because a mouse sensor does not measure dots. The two labels describe the same quantity, and every major mouse maker ships its software with a DPI field. If a spec sheet says 1600 CPI and the settings app says 1600 DPI, nothing is different. You can use either word in a conversation and be understood.

What DPI does not do is make you more accurate. A higher DPI means the pointer travels further for the same hand movement, and the game engine turns further for the same count. Whether that helps depends on the sensitivity you pair it with, which is why the useful number is not DPI on its own but DPI times in-game sensitivity.

One more term shows up on spec sheets: polling rate, measured in Hz. A 1000 Hz mouse reports its position every 1 ms, and an 8000 Hz mouse every 0.125 ms. Polling rate changes how smooth the input feels. It does not change how far the crosshair moves, which is the job of DPI and sensitivity. The W3C pointer events specification describes how a browser receives those counts as pointer movement, which is why the same mouse can feel different in a browser and in a game.

Worked example: 800 DPI at 0.35 sensitivity

Take an 800 DPI mouse and a Valorant sensitivity of 0.35. Multiply them and you get 280 eDPI. That single number is what most players compare, because it folds two settings into one.

To turn that into a distance, use the game's yaw value, which is the number of degrees the view turns per count. Valorant and CS2 both use 0.022 degrees per count. At 280 eDPI the mouse produces 280 times 0.022, or 6.16 degrees, per inch of travel. A full 360 turn needs 360 divided by 6.16, which is 58.4 inches, or 148.4 cm.

Put a ruler on the desk and 148 cm is about four and a half feet of mouse pad. That is a low sensitivity by office standards and a normal one for a tactical shooter, where the whole point is that a small hand tremor moves the crosshair by a fraction of a degree.

Change the DPI and keep the same feel by holding eDPI constant. At 1600 DPI the sensitivity that gives 280 eDPI is 0.175. At 400 DPI it is 0.70. All three setups need the same 148.4 cm for a 360 turn, so the muscle memory carries over.

Sensitivity, screen resolution and how the pointer feels

On the desktop, DPI and resolution together decide how fast the pointer crosses the screen. At the default Windows pointer speed, which is the sixth notch of eleven and a 1:1 mapping, the pointer moves one pixel per count. A 1920 pixel wide screen at 800 DPI therefore needs 2.4 counts to cross, which is 0.003 inches of travel, and the pointer feels fast because it is.

Move to a 3840 pixel wide screen and the same 800 DPI needs 4.8 counts, so the pointer feels half as fast. This is why a 4K monitor on an old 800 DPI mouse feels sluggish, and why the fix is either more DPI or a higher pointer speed in the OS. A 1600 DPI mouse restores the old feel on 4K, because 3840 divided by 1600 is 2.4 counts again.

Two settings break that clean relationship. The first is pointer acceleration, which Windows calls enhance pointer precision. It multiplies the movement based on how fast you move, so the same hand movement lands in different places depending on speed, and no DPI value can compensate. Turn it off for anything that needs consistency. The second is a game's own sensitivity curve, which is rarely linear across the whole slider.

Microsoft's documentation for the SystemParametersInfo function shows the mouse speed and acceleration values that the pointer slider writes. Set the slider to the middle notch for a 1:1 mapping, then leave it alone and tune DPI instead.

eDPI: one number to compare two setups

Effective DPI is mouse DPI multiplied by in-game sensitivity. It is not a real DPI, and no sensor runs at 280. It is a comparison tool, and it works because two setups with the same eDPI turn the same distance in the same game.

A player on 400 DPI at 2.0 sensitivity and a player on 1600 DPI at 0.5 both run 800 eDPI. Their hands move the same distance for a 360 turn, so a tip like "try 800 eDPI" transfers between them. That is the whole value of the number, and it is why sensitivity guides quote eDPI instead of raw sensitivity.

The catch is that eDPI only compares inside one game. Valorant at 280 eDPI and Overwatch 2 at 280 eDPI are not the same feel, because the two games use different yaw values. Valorant turns 0.022 degrees per count, and Overwatch 2 turns about 0.0066. The same 280 eDPI turns three times further per inch in Valorant, so the cm/360 distance differs by a factor of three.

Read the table by row, not by column. Doubling DPI doubles eDPI at a fixed sensitivity, and halving sensitivity brings it back. The middle cell, 800 DPI at 0.35, is the 280 eDPI that tactical shooter players land on most often.

cm/360: the distance that transfers between games

The centimeters per 360 turn figure is the physical distance your hand travels to spin the view once. It is the number that transfers between games, because it describes your body rather than a settings menu. The formula is 360 divided by eDPI times yaw, then multiplied by 2.54 to convert inches to centimeters.

At 280 eDPI in Valorant that is 148.4 cm. At 800 eDPI it is 52.0 cm. At 1600 eDPI it is 26.0 cm, which is roughly the width of a large mouse pad and about as fast as most players can aim with control. Below 20 cm the wrist does most of the work and the shoulder does none, which is fine for tracking games and hard for precision shots.

The 2.54 conversion is exact, since the inch has been defined as 2.54 cm since 1959. The NIST reference on units of length states the definition, and it is the reason a 58.4 inch turn is 148.4 cm rather than a rounded 148.

Both columns come from the same formula with a different yaw. That is the practical warning for anyone converting sensitivity between games: matching eDPI across games with different yaw values gives a completely different feel, and matching cm/360 is the reliable way to carry aim from one title to another.

Changing DPI without losing your aim

The safe way to change DPI is to change sensitivity in the opposite direction on the same day, then leave both alone for a week. Going from 800 to 1600 DPI means halving sensitivity from 0.35 to 0.175, which holds eDPI at 280 and keeps the 360 distance at 148.4 cm. Your hand does not know the difference, and the only thing that changes is how many counts the sensor sends.

People still switch, for two reasons. A higher DPI can reduce the visible step between counts on a very high resolution screen, and some sensors report more smoothly at 1600 than at 400. A lower DPI can reduce jitter and coil whine on a few models. Neither effect is large, and both are smaller than the effect of a week of practice.

Write the numbers down before you start, because mouse software often keeps a per profile DPI list and a game keeps its own sensitivity. A mismatch between the two is the most common reason a setup feels wrong after a software update.

Every row holds the same eDPI, so every row turns the same distance. The sensitivity figures are rounded to three decimals, which is why 280 over 3200 shows as 0.087 rather than 0.0875. Pick the DPI your mouse runs most cleanly at and read the sensitivity from that column. If a game caps its sensitivity slider, move to the next DPI column instead of fighting the cap.

Do you need a 26,000 DPI mouse?

No. The highest DPI a sensor can report is a marketing number, and almost nobody uses the top of the range. Most competitive players sit between 400 and 1600 DPI, and the 26,000 DPI headline on a box describes a setting that adds smoothing and produces counts faster than a human hand can generate them.

At 26,000 DPI one count is 0.00098 mm of travel, which is smaller than the vibration of a desk from a nearby fan. The sensor has to filter that noise, and filtering is the same thing as smoothing. A 1600 DPI setting on the same mouse is usually cleaner, and 1600 is already fine enough for a 4K screen at a 1:1 pointer speed.

What does matter on a spec sheet is the maximum tracking speed, measured in inches per second, and the acceleration rating, measured in g. A mouse that tracks 400 IPS will not lose the pad during a fast flick, and one rated at 50 g will not spin out when you stop hard. Those numbers describe real limits. The DPI ceiling does not.

Spend the difference on a larger mouse pad instead. Going from 148.4 cm per 360 turn to a comfortable 40 cm needs desk space, and no DPI setting creates space that is not there.

Sensor specifications vary by model and firmware. Treat the figures here as a guide to how the math works, and check the maker's own spec sheet for the limits of a specific mouse.