How to measure your hand for a mouse, and what size to get

To measure your hand for a mouse, lay it flat and measure from the first crease of your wrist to the tip of your middle finger. The finder counts under 17 cm (6.7 in) as a small hand, 17 to 19 cm as medium, 19 to 21 cm as big and over 21 cm (8.3 in) as XL.

Treat that as a starting point. Your grip moves the length, usually by a few millimeters: for an 18 cm hand, the finder aims for about 125 mm in a palm grip and 122 mm in a claw grip. The chart below lists its targets for every hand and grip, the same ones it uses to rank 1,524 mice.

How to measure your hand for a mouse

You need a ruler or a tape measure and about a minute.

1. Lay your mouse hand flat on a table, palm up, fingers together.
2. Find the first crease where your wrist meets your palm. That is zero.
3. Measure in a straight line to the tip of your middle finger.
4. Write it down in centimeters. If your ruler is in inches, multiply by 2.54.

Start at the crease, not at the heel of your palm. The heel sits higher, so your hand reads shorter and you can land a size too small.

How to measure hand width for a mouse

Guides disagree. Attack Shark measures across the knuckles, Voltcave across the palm with the thumb, UCLA's ergonomics office from the palm's edge by the index finger to the ring finger's knuckle. Go across the knuckles and leave the thumb out, since it sits on the side of the mouse anyway.

Width is the other number that decides fit, most of all in a claw or fingertip grip, where the thumb and ring finger pinch the sides. Rocket Jump Ninja, who has reviewed mice for ten years, suggests a mouse about 60% of your hand measurements, or lining up a measurement across your hand with the mouse's grip width, because the measurement that actually matters on mice is where we're holding them. For length he uses your middle finger, back to the knuckle.

The finder doesn't ask for your hand width. It reads width from the shell instead: how wide a mouse is for its length counts toward the fit score, and so does an overall size rating that takes in width and height. Of the 1,373 flat mice in our catalog (no verticals or trackballs), 1,126 are 60 to 68 mm wide, and you can feel those 8 mm between thumb and ring finger. If your hand is narrow or broad for its length, compare the widths on your shortlist with a mouse you've held.

Mouse size chart by hand size and grip

The length the finder aims for, in millimeters front to back, by hand length from the wrist crease and grip. A mouse a few millimeters either side can fit just as well, so read each number as the middle of a range.

With no grip chosen, as on our guides for each hand size, the finder uses the claw column. For a small hand every grip but fingertip lands on 117 or 118 mm. The palm target sits low on purpose, on the border between small and medium shells in our catalog, so a small hand in a palm grip gets both sizes.

The fingertip column covers two ways to hold a mouse: a tiny shell cut off just behind the buttons, or the front half of a regular one. For small and medium hands its number follows the fingertip shells in our catalog, which run about 50 to 107 mm long. For a big or XL hand it moves up to compact regular mice, which a big hand can hold by the front.

For a big hand and a symmetrical mouse, the finder aims 3 mm shorter, because only 38 of the 946 symmetrical mice in our catalog reach 128 mm. Ergonomic shells run longer and get the full number.

Check the chart against a mouse you've held

If you've held one of these, its length tells you where you sit. One that felt short means you're probably a size up.

Each grip has its own list: palm, relaxed claw, claw and fingertip, plus one for each hand size and grip, such as medium hands in a claw grip. Not sure which grip you use? Claw vs palm grip shows how to tell.

Why your grip changes the size you need

In a palm grip your whole hand lies on the mouse, so the finder aims for buttons that end about where your fingertips do, though some palm players like their fingers a little past the edge. It's the longest target and the finder's strictest: the fit score drops fast once a palm grip mouse is more than about 5 mm off. A claw grip arches the fingers, which takes a few millimeters off the reach.

Fingertip is where length comes down to taste, and the finder is forgiving here: a fingertip mouse can be about 16 mm off before its score drops as far as a palm mouse 5 mm off, so the fingertip lists hold both tiny shells and regular mice held by the front half. If the mouse you hold by the front is longer than anything on them, read the claw column.

Does the 60% rule work?

Many guides say a mouse should be about 60% as long as your hand. Attack Shark calls it a rule of thumb and suggests 65 to 70% for a palm grip. Rocket Jump Ninja gives 60% as a rough guide and leans small on purpose, finding smaller mice easier to aim; for length he simply uses your middle finger.

At 60% of length, an 18 cm hand gets a 108 mm mouse. Only about one mouse in twenty in our catalog is that short (the typical one is 122 mm), so the length rule points a medium hand at the smallest shells, and the finder's palm target is longer.

The finder's palm targets come to about 73% of a 16 cm hand but 65% of a 20 cm one, because mice vary in length much less than hands do: four in five flat mice are 116 to 128 mm long.

Length is only half the fit

Two 122 mm mice can feel nothing alike, because width, height, the hump and the sides change how a mouse fills your hand. A palm grip usually suits a fuller back, and a claw grip a hump set further back for the base of the palm to brace on, though plenty of players like it the other way round. The finder scores all of that once it knows your hand and grip.

Hand size only narrows the field. Matty, an aim trainer with Voltaic, says measuring your hand isn't the most critical step and calls it a rough estimate. He picks a mouse by how comfortable it feels to aim with.

What if you're between two sizes?

If you measure close to a border, such as 17.0 or 19.0 cm, run the finder once with each size. With a fingertip grip it matters least. With a palm grip the finder treats a mouse a little short and a little long the same, so let shape decide: compare the lists for small and medium hands, or medium and big, and see which shells feel familiar.

Questions

How do I measure my hand for a vertical mouse?

The same way, wrist crease to middle fingertip. Evoluent suggests its small models for hands of 7.0 in (178 mm) or less, and Logitech sells the Lift for small to medium hands. It is 108 mm long, against 120 mm for the MX Vertical.

Is an 18 cm hand small or medium?

Medium, right in the middle of the 17 to 19 cm range. The finder aims for about 125 mm in a palm grip or 122 mm in a claw grip.

What size mouse should I get?

Measure your hand, work out your grip and read a starting length off the chart. The finder then turns that into actual shapes, ranked by fit, with width, height and the hump counted in.