Adult size guide

Measure the foot, not the shoe

The measurements in this chart refer to the foot, never to the insole or the outsole of the shoe.

It takes two minutes and you only need things you already have at home: a sheet of paper, a pencil and a ruler.

  • Put the sheet of paper on the floor, right up against a wall.
  • Place the foot on it, with the heel touching the wall and the foot completely flat. It's best done standing up, with the weight spread evenly across both feet.
  • Mark on the paper where the longest toe ends. It isn't always the big toe.
  • Take the foot away and use the ruler to measure from the edge of the paper to the mark. That distance, in centimetres, is the foot length.
  • Do the same with the other foot and go by the larger measurement.

Measure at the end of the day, when the foot is at its largest, and with bare feet.

Size chart · adult line
Foot length EU UK
23.0 cm 36 3.5-4
23.6 cm 37 4.5
24.3 cm 38 5-5.5
25.0 cm 39 6
25.6 cm 40 6.5-7
26.3 cm 41 7.5
27.0 cm 42 8-8.5
27.6 cm 43 9-9.5
28.3 cm 44 10
29.0 cm 45 10.5-11
29.6 cm 46 11.5

How to read the chart

Each row shows, in centimetres, the foot length from which that size starts. Find the row whose value is equal to or just below your measurement: that's your size.

An example, because it's the most common question: if your foot measures 24.0 cm, your row is the 23.6 cm one and your size is 37. Size 38 doesn't start until 24.3 cm.

The UK column is an approximate equivalent, useful if you're used to buying shoes in that sizing system. The reliable reference is the centimetre.

This guide covers sizes 36 to 46, which is the size range of the adult line. Children's footwear goes up to size 41, so between 36 and 41 the two guides overlap: the one that applies is the guide for the line of the model you're interested in. They're different lasts and each chart is built on its own.

Questions about choosing a size

My measurement falls between two rows. Which size should I choose?

The one in the row just below your measurement, because each row marks the point where that size starts. With 24.0 cm, for example, the size is 37: size 38 doesn't start until 24.3 cm.
Do I measure the foot or the insole of the shoe?

The bare foot. Neither the insole nor the outsole is a reliable reference: both are larger than the foot that goes inside, and measuring them leads to a size bigger than the one needed.
Each foot gives a different measurement. Which one do I go by?

The larger of the two. It's normal for one foot to be slightly longer than the other, and the size is always chosen by the longer one.
I usually wear a UK or US size. How do I find mine?

If you wear a UK size, the chart gives you an approximate equivalent. If you wear a US size, measure the foot: equivalents between sizing systems aren't exact and vary from one brand to another. Find your measurement in the first column.
When is the best time to measure?

At the end of the day, when the foot is at its largest.
I'm looking for a size below 36. Where can I find it?

In the children's size guide, which covers sizes 18 to 41 and gives the foot measurement in centimetre ranges. If you have any questions about a particular model, email us at info@biomecanics.com or call us on (+34) 966 633 941.