Key takeaways
- Measure hand length from middle-fingertip to the wrist crease, not the palm.
- Tiers: under 16.9cm Small, 17–19.5cm Medium, over 19.6cm Large.
- One class off ruins the feel — measure before you buy.
How to measure
Sit up straight, rest your hand flat and relaxed on the desk, and measure from the tip of your middle finger to the wrist crease — the fold at the base of the palm, not the palm itself. Measure length; width (across the palm, just below the knuckles) helps too but length is what most size charts use.
The size tiers
As a starting point, hand length maps to a mouse size class like this (the common size-chart breaks sit at 16.9cm and 19.6cm). These are not strict rules — grip and preference shift you off them.
| Hand length | Class | Mouse size |
|---|---|---|
| Under 16.9cm | Small | Compact / small |
| 17–19.5cm | Medium | Medium |
| Over 19.6cm | Large | Full-size |
Why one size class off ruins the feel
A mouse too large for your hand forces a claw or fingertip hold on a shape built for palm, and your fingers either overreach or cramp. Too small and a palm grip has nowhere to rest, so the hand clenches and tires. Get the class right and the grip you naturally use finally has a shape to sit in — that is where tracking and comfort come from.
Measure once, honestly. Reaching for a "pro mouse" that is the wrong size class will not make you aim like the pro; it will just make your hand work harder.