European Shoe Size: The Complete Conversion Guide

A size 39 bought in Paris, a 39 ordered from an American site and a 39 out of an Asian factory don't put the same shoe on your foot. A conversion chart solves part of the problem. What actually settles it is one number almost nobody knows: the length of their own foot in centimetres.

Measure your foot once, use it forever

Five minutes, a sheet of A4, a pencil and a skirting board.

1. Do it at the end of the day. Feet swell by 3 to 5 % between morning and evening. A shoe tried on at 9 am can pinch by 7 pm.
2. Keep on the socks you normally wear with that kind of shoe. A thick sports sock easily costs you half a size.
3. Put the sheet against the wall, heel touching the skirting board, standing, weight spread across both feet. Measured sitting down, a foot reads shorter. That's the most common mistake.
4. Draw the outline holding the pencil upright. Tilted, it adds several millimetres.
5. Measure from the heel to the longest toe, which isn't always the big toe.
6. Do the other foot.

Keep the larger of the two figures. Almost everyone has one foot longer than the other, often by 2 to 5 mm, and you always fit the bigger one.

The conversion chart, from 34 to 46

The centimetres shown are foot length, not insole length: the manufacturer already adds 5 to 10 mm of room inside the shoe.

Two traps come up constantly. First, US men's sizes sit about one and a half points below women's. A European 42 reads US 10.5 in women's but US 9 in men's, and an order placed off the wrong column arrives two sizes out. Second, half sizes don't exist in the European system. A 38.5 only exists in UK or US sizing, which is why "I'm between two sizes" is the question we get most.

Between two sizes, the material decides

"Size up" is true on average and wrong case by case. What matters is how much the shoe can move with the foot.

Knitted mesh uppers widen by a few millimetres with wear. On models like the SNEEK, going up a size buys room without the heel starting to slip. A sandal with elastic or adjustable straps closes the gap on its own, which covers most of the orthopedic sandals range.

A court shoe forgives nothing. One size up and the foot slides forward, the forefoot ends up squeezed where the shoe narrows, and the heel lifts with every step. On that kind of model, stay at your usual size and look for width instead.

Width, the dimension nobody measures

Two feet both 24.5 cm long can need two different sizes. Length gives you the size, width gives you the comfort, and depending on the last used, the same number can come out noticeably narrower.

Three signs the problem is width and not length: the seam is still printed on the side of your foot after a day's wear, you slip your shoes off every afternoon, or the upper wears through first on the outer edge. Going up a size fixes none of that. The shoe just gets too long, the foot slides forward and the problem moves to your toes. Look for a soft upper, an adjustable strap, or a model listed as wide fit.

Your size isn't fixed for life

Feet spread over the years. Ligaments loosen, the arch drops a little, and gaining half a size — sometimes a full one — between 30 and 60 is ordinary. Pregnancy does the same thing and it doesn't always go back. If your last measurement is ten years old, redo it before ordering. It's quicker than a return.

What about our own models?

Our shoes fit true to size: take your usual one. On the SNEEK Comfort Sneakers, if you're hesitating between two, take the larger — the mesh handles it. On sandals, if your feet swell late in the day or you have a wide foot, sizing up is the right call. Every product page repeats the guidance for that specific model.

And if the size still isn't right, trying costs nothing: returns are accepted for 30 days after delivery, and shipping is free over €35 in Europe and North America.