Size Guide

Rock Rat is sized by the length of your foot in inches — not by shoe size.

That's deliberate. Climbing shoe sizing is a mess: a 42 in one brand is a 40.5 in another, half the market lists EU sizes, and every climber downsizes by a different amount. A shoe size tells us almost nothing about the dimensions we actually have to fit.

An inch is an inch. Anyone with a ruler gets the same reading, and it means the same thing in every gym on earth. Measure once and you'll know your size for good.

Measure your foot

Two minutes. Do it at the end of the day — feet swell, and you want the bigger number.

1. 1Put a sheet of paper on a hard floorOne edge flat against a wall. Skip the carpet — it compresses and throws the reading off.
2. 2Stand on it, heel against the wallStand, don’t sit. Your foot spreads under your body weight, and the spread foot is the one that has to fit.
3. 3Curl your toes the way they curl in your climbing shoesThis is the step that matters. If you downsize hard and climb with your toes properly scrunched, scrunch them. If your shoes are a comfortable all-day fit, barely curl at all. Rock Rat fills the shoe — and your shoe is holding the scrunched foot, not your relaxed street foot.
4. 4Mark the tip of your longest toeIn that curled position. It isn’t always the big toe. Hold the pencil upright so you don’t add length.
5. 5Measure from the wall edge to the markA ruler or a tape measure, in inches. That number is all you need.
6. 6Do both feet and use the longer oneThey’re rarely identical. Size to the bigger foot — the smaller one will be fine.

Want a second opinion? Measure the shoe instead. Slide a tape measure into your climbing shoe, flat along the sole, with the heel pushed all the way back, and read where the inside of the toe box ends. That's the exact length Rock Rat has to fill — the curled-toe measurement above is just a quicker way of arriving at the same number.

Find your size

Land right on the line between two sizes? Size down. The smaller one can always dial shorter if you measured a touch long. The bigger one can't go below its shortest setting, and a tree that's too long won't seat properly in the shoe. Too short just means less tension; too long is the error you actually don't want.

Measuring under 8.6" or over 11.4"? Rock Rat doesn't cover your foot yet — email us at hello@rock-rat.com before you order and we'll tell you straight.

Every size adjusts

A size isn't one fixed length. Every Rock Rat has 3 settings — shortest, middle, longest — so the range in the table above is the adjustment span. Land anywhere inside it and there's a setting for you.

• Small8.6 · 9.1 · 9.6 in
• Medium9.6 · 9.9 · 10.2 in
• Large10.2 · 10.8 · 11.4 in

Set it once to the number you measured, and leave it there. If your shoes stretch out over a season, take it up a setting to keep the tension on.

Where your judgment comes in

The table gets you the right tree. How aggressively your shoes fit is your call, and you're the only one who knows it — that's why step 3 asks you to replicate your own toe curl rather than handing you a formula.

Some climbers live a full size below their street shoe with their toes properly folded and their arch under tension; others sit close to true-to-fit and can walk around in them. Both are legitimate. Measure the foot you actually climb on, and the table will find you.

And if you call it wrong, size exchanges are free — that's what they're for. See shipping & returns.