Mouse DPI Calculator: Understanding eDPI and cm/360

Ask two competitive gamers about their mouse settings and you will likely hear very different numbers. One plays at 400 DPI and 2.0 in-game sensitivity; another swears by 800 DPI and 1.0 sensitivity. On the surface these sound like opposite setups—yet both players may aim at exactly the same speed. The reason is that raw DPI and raw sensitivity tell you almost nothing on their own. What actually matters is how they combine, and that is where eDPI and cm/360 come in.

This guide explains the two numbers every serious first-person-shooter player should know. We will cover what DPI and sensitivity really mean, how eDPI collapses them into a single comparable figure, how cm/360 describes your sensitivity in pure physical terms, and how to use these values to dial in an aim that feels consistent no matter what hardware or game you switch to.

What Is Mouse DPI and In-Game Sensitivity?

DPI (dots per inch), sometimes called CPI for counts per inch, is a hardware setting on your mouse. It defines how many “counts” the sensor reports for every inch you physically move the mouse across the desk. A higher DPI means the cursor or camera moves further for the same hand motion.

In-game sensitivity is a software multiplier applied on top of those counts inside a particular game. A sensitivity of 2.0 makes the camera turn twice as far per count as a sensitivity of 1.0.

Because the final aim speed depends on both values multiplied together, comparing just one of them is meaningless. A player at 1600 DPI with 0.5 sensitivity aims identically to a player at 400 DPI with 2.0 sensitivity. To compare fairly, we need a combined metric.

How eDPI Works

eDPI, or effective dots per inch, is the elegant solution. The formula could not be simpler:

eDPI = DPI × in-game sensitivity

By multiplying the hardware DPI by the software sensitivity, eDPI produces one number that represents your true, effective aiming speed. Both of the players above have an eDPI of 800 (1600 × 0.5 and 400 × 2.0), which instantly tells you they aim at the same speed despite their different raw settings.

This is why the professional scene reports eDPI rather than DPI or sensitivity alone. When a pro says their eDPI is 800, you know exactly how fast they turn, and you can replicate that feel on your own mouse regardless of what DPI you happen to run. It removes the ambiguity entirely and makes cross-setup comparison trivial.

A Worked eDPI and cm/360 Example

Suppose you play at 800 DPI with an in-game sensitivity of 1.5 in a Source-engine game such as CS2, which uses a yaw constant of 0.022 degrees per count.

First, the eDPI:

eDPI = 800 × 1.5 = 1200

Now the cm/360, which measures how far you must physically move the mouse to spin a full 360 degrees:

cm/360 = (2.54 × 360) ÷ (DPI × sensitivity × yaw)
       = 914.4 ÷ (800 × 1.5 × 0.022)
       = 914.4 ÷ 26.4
       ≈ 34.62 cm

So to turn all the way around, you would sweep the mouse about 34.6 centimeters across the desk. If you dropped to 400 DPI and 2.0 sensitivity—same eDPI of 800—the cm/360 would change to about 51.95 cm, because the yaw math depends on the individual DPI and sensitivity, not just their product. This subtlety is worth remembering: eDPI captures aim speed, while cm/360 captures the physical distance, and the two only line up perfectly when the yaw is identical.

What cm/360 Tells You

cm/360 is the most hardware-independent way to describe sensitivity because it is expressed in real-world centimeters. The formula uses the game’s yaw constant to convert counts into degrees:

cm/360 = (2.54 × 360) ÷ (DPI × sensitivity × yaw)

The 2.54 converts inches to centimeters, 360 is a full rotation in degrees, and the yaw defines how many degrees each mouse count turns the camera. For Source-engine titles the yaw is 0.022; other engines use different constants, so the calculator lets you change it.

A low cm/360 (say 20 cm) means a small hand movement whips you all the way around—fast but twitchy. A high cm/360 (say 50 cm) means you need a big sweep to turn—slower but far easier to aim precisely. Most competitive players settle somewhere between 25 and 50 cm, favoring arm aim over wrist flicks for consistency.

How to Use the Mouse DPI Calculator

The tool needs only two required inputs and one optional one:

1. Mouse DPI – the value configured in your mouse software, such as 400, 800, or 1600.
2. In-game sensitivity – the sensitivity slider value from your game, such as 1.5.
3. Yaw – optional; leave it at the default 0.022 for Source-engine games, or enter your game’s specific constant.

The calculator immediately returns your eDPI and your cm/360 (along with the equivalent in inches). Because it recalculates as you type, you can experiment: lock your target eDPI and see how different DPI-and-sensitivity combinations change the physical turn distance.

Tips for Finding Your Ideal Sensitivity

• Set DPI once, then tune in-game. Pick a standard DPI like 400 or 800 and adjust only the in-game sensitivity. This keeps your settings portable and avoids sensor interpolation issues at unusual DPI steps.
• Aim for a consistent cm/360 across games. Muscle memory is built on physical distance, not numbers. Match your cm/360 between titles so a 180-degree turn feels the same everywhere.
• Start lower than you think. New players often run too fast. A cm/360 around 35–45 cm encourages steadier, arm-driven aim that improves accuracy over time.
• Change one variable at a time. When experimenting, hold everything else constant so you can feel the effect of each adjustment clearly.

Common Use Cases

Players reach for an eDPI calculator whenever they change hardware or games. Buying a new mouse with a different DPI? Recompute the sensitivity that preserves your eDPI. Switching from CS2 to another shooter? Match the cm/360 so your aim transfers. Copying a pro’s published eDPI? Convert it to your own DPI in seconds. Coaches and teammates also use these numbers to standardize settings across a roster so everyone trains with comparable sensitivity.

Conclusion

Raw DPI and raw sensitivity are almost useless in isolation, but multiplied together they reveal your true aim speed through eDPI, and translated into centimeters they describe your setup physically through cm/360. Understanding both lets you compare your sensitivity to anyone, migrate settings between mice and games without losing muscle memory, and deliberately tune your aim for either speed or precision. Try our free Mouse DPI Calculator for instant results.