How to measure your feet

Everything else on this site depends on two numbers, and almost nobody has them. Shop measuring devices give you a size label rather than a measurement, and they are calibrated for conventional fitting allowances that are too tight for barefoot footwear.

The paper method takes four minutes, costs nothing, and gives you a number in millimeters you can compare directly against the internal lengths barefoot brands publish. It also gives you a dated record, which turns out to matter: people who switch to minimal footwear commonly find their forefoot measurement grows over the following months, and a tracing from six months ago is the only way to know.

The steps above are the whole procedure. Two of them are the ones people get wrong, and both matter by several millimeters.

Your foot is not a rigid object. Put weight on it and the arch flattens, the foot spreads, and the length increases — commonly by 3 to 6 mm. If you trace sitting down, you get the dimensions of a foot that does not exist when you are walking on it, and you will buy a shoe that is a half size too short without knowing why.

Stand up. Put real weight through the foot. If you need to brace a hand on a wall, brace a hand on a wall.

It is awkward to trace your own foot, and the natural move is to tilt the pen in underneath it. That adds 2 to 4 mm of phantom foot all the way round, and because it adds it to the width as well as the length it can push you toward the wrong brand entirely.

Keep the pen vertical and let the line sit just outside your skin. If you cannot reach comfortably, get someone else to do it, or stand on the paper and mark just the heel and the longest toe with two decisive pen strokes rather than tracing the whole outline.

The tracing also answers the foot-shape question for free. Look at the front edge of your outline: do the toes step down in a smooth diagonal from a clearly longest big toe, are the first three near-equal, or is the front edge almost straight across? That is the information foot shape types turns into a brand shortlist.

Exactly the same method, with two differences: do it more often, and expect it to be a two-person job. Young children do not reliably report that a shoe is too small — they curl their toes and adapt, so nothing looks wrong from outside. Re-trace roughly every six to eight weeks for under-threes and every couple of months after that, and keep the dated tracings. Kids' shoes.

Once you have the numbers, the next step is the sizing guide, which turns them into an order. If you already know your size and want to shop, the fit hub indexes every page by what your foot needs.