How to use the shoe size converter
- Under Convert from, pick the size system you know, such as US men's or EU, or pick foot length if you've measured your foot.
- Enter the size or the length.
- Under Convert to, pick the system you want. The big answer shows that size, and the list under it shows every system at once.
- Scroll down for full adult and kids' size charts.
To measure your foot, stand on a sheet of paper with your heel against a wall, mark the tip of your longest toe, and measure from the wall to the mark. Measure both feet in the evening, when feet are at their largest, and use the longer one.
How shoe sizes are converted
Every system is based on the length of the foot or the shoe last, just with different units and starting points. The converter turns your size into a foot length, then into each other system:
US and UK sizes step by a barleycorn, an old unit of ⅓ inch (8.47 mm), which is why the formulas multiply by 3. EU sizes use the Paris point of ⅔ cm (6.67 mm), so one EU size is a little smaller than one US or UK size. Japanese sizes, like the international Mondopoint system, are simply the foot length. The constants allow for the extra length a shoe needs beyond the foot. These are the commonly published approximations; results are rounded to the nearest half size.
Worked example
The defaults convert a US men's 9 to EU:
- Foot length: (9 + 22) ÷ 3 = 10.33 in, or 10.33 × 2.54 = 26.2 cm
- EU: 1.5 × 26.2 + 2 = 41.4, rounded to the nearest half: 41.5
- UK: 3 × 10.33 − 23 = 8
- US women's: 3 × 10.33 − 20.5 = 10.5
- Japan: 26.2 cm rounds to 26
Going the other way, an EU 42 is a foot of (42 − 2) ÷ 1.5 = 26.7 cm (10.50 in), which is a US men's 3 × 10.50 − 22 = 9.5. A child's US 10C is a foot of 6.58 in (16.7 cm), so it's an EU 1.5 × 16.7 + 2 = 27.
Adult size chart
| US men's | US women's | UK | EU | Japan | Foot (cm) |
|---|---|---|---|---|---|
| 6 | 7.5 | 5 | 37.5 | 23.5 | 23.7 |
| 7 | 8.5 | 6 | 39 | 24.5 | 24.6 |
| 8 | 9.5 | 7 | 40 | 25.5 | 25.4 |
| 9 | 10.5 | 8 | 41.5 | 26 | 26.2 |
| 10 | 11.5 | 9 | 42.5 | 27 | 27.1 |
| 11 | 12.5 | 10 | 44 | 28 | 27.9 |
| 12 | 13.5 | 11 | 45 | 29 | 28.8 |
The converter shows the full chart in half sizes from men's 4 to 15, and a kids' chart from 2C to 7Y.
Why brand charts differ
There's no single international standard that every maker follows. Brands use their own lasts, and many athletic brands publish charts where a US men's 9 is an EU 42 or 42.5 and a Japanese 27, about half a size to a full size above the formula values. Women's sizes are usually men's + 1.5 in the US, but some brands use + 1. Width, toe shape and materials change the fit too. Use the converter to get close, then check the brand's own chart and its stated foot length for each size.
Frequently asked questions
Is EU sizing the same for men and women?
Yes. EU sizes are unisex and based only on length, so a man's and a woman's EU 40 are the same length. US sizes are the ones that differ: a women's US size is usually 1.5 larger than the men's size for the same foot.
How do US kids' sizes work?
Children's sizes run from about 0C to 13.5C for toddlers and little kids, then start again at 1Y for youth (big kids) up to about 7Y. The largest youth sizes overlap with small adult sizes, so teens often move into men's or women's sizes from about 6Y or 7Y.
What is my size in Japanese sizing?
Japanese shoe sizes are your foot length in centimeters, usually in half-centimeter steps. If your foot measures 25.3 cm, look for a 25.5. Some brands label the same number as "JP" or "CM".
Should I size up between two sizes?
Usually, yes, especially for running shoes, hiking boots and anything worn with thick socks. Your feet swell during the day and when you exercise. Aim for about a thumb's width (1 to 1.5 cm) between your longest toe and the end of the shoe.
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