About eDPI Calculator
eDPI — effective dots per inch — is simply your mouse DPI multiplied by your in-game sensitivity. It exists because the two settings are interchangeable: 800 DPI at sensitivity 2 feels identical to 1600 DPI at sensitivity 1, and multiplying them collapses that into one number.
It is genuinely useful for comparing players in the same game, which is why professional player lists quote it. It is worth being clear about its limit though: eDPI is meaningless across games. An eDPI of 800 in Counter-Strike and 800 in Overwatch are completely different speeds, because each game applies its own constant before turning you.
cm/360 is shown alongside for exactly that reason. It measures the physical distance your hand moves for a full turn, so it means the same thing everywhere and is the figure to compare when the games differ.
How to work out your eDPI
Find your mouse DPI
In your mouse software, or on the manufacturer's page. It is often 800 or 1600 by default.
Find your in-game sensitivity
In the mouse or controls section of the game's settings.
Read the numbers
eDPI for comparing within your game, and cm/360 for comparing with anyone else.