Mouse sensitivity math: cm/360, eDPI, and why pros recalibrate
What 'sensitivity' actually means
Open a mouse settings menu and you will see a single slider labelled sensitivity, but that number is close to meaningless on its own. A sensitivity of 2.0 in one game can turn your view twice as fast, half as fast, or about the same as 2.0 in another, because every engine multiplies the slider by its own hidden constant. Add the mouse's own DPI (dots per inch) on top, and two players who both say they 'play on 2.0' can have wildly different aim.
To compare settings or carry them between games you need units that strip out these hidden variables. Two units do that: eDPI and cm/360.
eDPI: comparing within a game
eDPI ('effective DPI') is simply your mouse DPI multiplied by your in-game sensitivity. A player on 800 DPI and 0.5 sensitivity has an eDPI of 400 — exactly the same as a player on 400 DPI and 1.0 sensitivity. Both move the crosshair the same amount for the same hand movement, even though their raw numbers look different.
eDPI is the right tool when you want to compare your sensitivity to a teammate's or a pro's in the same game. It is not a cross-game number: because each engine applies its own multiplier, an eDPI of 400 in one shooter does not produce the same turn speed as 400 in another. eDPI normalises away DPI, but not the engine.
cm/360: the only truly cross-game unit
cm/360 measures the physical distance — in centimetres — your mouse must travel to rotate your view a full 360 degrees. It is the most honest sensitivity unit because it describes something real and physical, independent of any game's internal math. A lower cm/360 means a higher sensitivity (you turn around with a small flick); a higher cm/360 means a lower sensitivity (you need a longer swipe).
Because it is measured in real distance, cm/360 is the unit that transfers between games. If two games are set to the same cm/360, a 180-degree flick feels identical in both, regardless of their sensitivity sliders or DPI. As a general pattern, competitive players tend to sit at lower sensitivities (higher cm/360) than casual players, because longer swipes give finer control for precise aiming — though the exact value is a personal fit, not a magic number.
The conversion math
The chain from hand movement to on-screen rotation runs: physical distance, then counts (set by DPI), then degrees (set by the in-game sensitivity and the engine's internal scalar). To keep the same feel across two games you hold cm/360 constant and solve for the new in-game sensitivity. In practice this means: when you switch games you do not copy the sensitivity number across — you convert it so the physical cm/360 stays the same.
The variable that trips people up is each engine's internal rotation constant, often called yaw. Two games with identical DPI and identical sensitivity sliders can still have different cm/360 because their yaw differs. This is why a dedicated converter matters: it accounts for the per-game scalar so your muscle memory survives the move. The sensitivity calculator on this site does exactly that.
Why pros recalibrate
Aiming is muscle memory built around one specific cm/360. Your brain learns that a flick of a certain physical distance rotates the view a certain amount. Anything that breaks that mapping forces a recalibration: a new game (different yaw), a new mouse (different sensor or DPI step), a different mousepad or amount of desk space, or even a change in monitor distance and field of view (FOV), which alters how much on-screen movement a given rotation produces.
This is why professional players are conservative about changing settings and deliberate when they do. They lock a cm/360, play thousands of hours at it, and only re-tune for a concrete reason. When they do change — say, lowering sensitivity to steady their aim — they treat it as a fresh calibration: drop the value, then grind aim drills until the new distance feels automatic. The lesson for everyone else is that consistency beats the specific number. A mediocre sensitivity you have fully internalised will out-aim a 'perfect' one you switched to yesterday.
Practical takeaways
Measure your cm/360 and write it down. It is the one number worth knowing; DPI and in-game sensitivity are just two ways to reach it.
Convert by cm/360, never by the slider. When you pick up a new game, match the physical distance, not the number on screen.
Turn off mouse acceleration. Acceleration makes the distance-to-rotation mapping non-linear, so the same flick gives a different turn depending on how fast you move — the enemy of muscle memory. Check both the operating system and the in-game setting.
Do not copy a pro's exact value. Their cm/360 fits their arm length, grip, and desk. Use it as a starting range, then adapt to your own space.
Recalibrate on purpose, not by accident. After any hardware, game, or FOV change, expect a short adjustment period and drill it deliberately rather than fighting it mid-match.