How the Shoe Size Calculator Works
A shoe size is not a random number. It is a measure of length, and the different systems around the world simply count in different steps. The United States, the United Kingdom and Europe each have their own scale, and the men's and women's scales are different too. The Shoe Size Calculator changes a size from one system to another, and it can also find your size from the length of your foot.
What you enter
- What you know: a US shoe size, or the length of your foot.
- The category: men's or women's US sizes.
- The US size, in whole or half sizes. Or the length of your foot, in centimeters or inches.
How the sizes are worked out
Each system is based on the length of the foot, so the calculator works from the length:
foot length in inches = (men's US size + 22) / 3 foot length in cm = foot length in inches x 2.54 EU size = 1.5 x (foot length in cm + 2), rounded to a half size UK size = men's US size - 1, or women's US size - 2 women's US size = men's US size + 1.5
- US: each size is one third of an inch, which is 0.85 cm.
- UK: it uses steps of the same length as the US, but starts from a different point, so the UK size is smaller.
- EU: sizes are counted in Paris points. One point is two thirds of a centimeter, so a European size is smaller than a US size, and there are about 1.27 European sizes for each US size. The 2 cm are the extra length that a shoe has beyond the foot.
A worked example
You wear a men's US size 9.
| Step | Result |
|---|---|
| Foot length in inches ((9 + 22) / 3) | 10.33 in |
| Foot length in centimeters (10.33 x 2.54) | 26.2 cm |
| EU size (1.5 x (26.2 + 2)) | 42.37, which is 42.5 |
| UK size (9 - 1) | 8 |
| Women's US size (9 + 1.5) | 10.5 |
A women's US size 8 is different. It is the same as a men's 6.5, so the foot is 24.1 cm, the EU size is 39, and the UK size is 6.
Men's sizes
| US | EU | UK | Foot length | Women's US |
|---|---|---|---|---|
| 6 | 38.5 | 5 | 23.7 cm | 7.5 |
| 7 | 40 | 6 | 24.6 cm | 8.5 |
| 8 | 41 | 7 | 25.4 cm | 9.5 |
| 9 | 42.5 | 8 | 26.2 cm | 10.5 |
| 10 | 43.5 | 9 | 27.1 cm | 11.5 |
| 11 | 45 | 10 | 27.9 cm | 12.5 |
| 12 | 46 | 11 | 28.8 cm | 13.5 |
| 13 | 47.5 | 12 | 29.6 cm | 14.5 |
Women's sizes
| US | EU | UK | Foot length | Men's US |
|---|---|---|---|---|
| 5 | 35.5 | 3 | 21.6 cm | 3.5 |
| 6 | 36.5 | 4 | 22.4 cm | 4.5 |
| 7 | 38 | 5 | 23.3 cm | 5.5 |
| 8 | 39 | 6 | 24.1 cm | 6.5 |
| 9 | 40.5 | 7 | 25.0 cm | 7.5 |
| 10 | 41.5 | 8 | 25.8 cm | 8.5 |
| 11 | 43 | 9 | 26.7 cm | 9.5 |
Chart: foot length by size
Each block is about 0.75 cm. Green bars are men's sizes, and blue bars are women's sizes.
Men's US 6 ████████████████████████████████ 23.7 cm Men's US 8 ██████████████████████████████████ 25.4 cm Men's US 10 █████████████████████████████████████ 27.1 cm Men's US 12 ███████████████████████████████████████ 28.8 cm Men's US 13 ████████████████████████████████████████ 29.6 cm Women's US 5 █████████████████████████████ 21.6 cm Women's US 7 ███████████████████████████████ 23.3 cm Women's US 9 ██████████████████████████████████ 25.0 cm Women's US 11 ████████████████████████████████████ 26.7 cm
Finding your size from your foot
Choose "I measured my foot" and enter the length. The calculator turns it into a size, rounded to the nearest half size. For example, a foot of 26.5 cm is 10.43 inches. The men's size is 3 x 10.43 - 22 = 9.3, which is 9.5, with EU 42.5 and UK 8.5. In women's sizes it is a US 11.
To measure your foot:
- Stand on a sheet of paper, with your heel against a wall.
- Mark the tip of your longest toe. It is often the big toe, but not always.
- Measure from the wall to the mark. Do this for both feet, and use the longer one.
- Measure in the evening. Feet are a little bigger at the end of the day.
Why sizes are different from brand to brand
The system is an agreement, but every maker uses its own lasts, which are the shapes around which the shoes are built. A running shoe may fit half a size differently from a leather shoe, and a boot differently from a sandal. A size in Europe can also be a whole number or a half number, depending on the maker. For this reason:
- Use the calculator as a guide, and check the size chart of the brand.
- If you are between two sizes, or your foot is wide, choose the larger size.
- Try shoes on in the evening, with the socks that you will wear.
- There should be about a thumb's width, 1 to 1.5 cm, between the longest toe and the end of the shoe.
Tips for buying shoes
- Measure both feet. Many people have one foot that is slightly bigger.
- Check the width as well as the length. A shoe that is too narrow hurts, even if the length is right.
- Children's feet grow quickly. Check the fit every few months. This calculator is for adult sizes.
- Buying online: read the size guide, and check the return policy.
What this calculator does not include
- Children's sizes, and the width of the foot.
- The exact size charts of individual brands.
- Other systems, such as the Japanese, Chinese and Australian sizes, and the Mondopoint system.
This tool gives a general guide only. Sizes differ between brands, so check the size chart of the brand before you buy.