Understanding Shoe Size Conversion
Shoe size has no global standard. US, UK, EU, Japan, and China each use different scales and formulas. This converter estimates size from foot length (in cm, mm, or inches) so you can get equivalent sizes across systems. Choose Adults, Kids (5–12), or Infants (0–4) for the right formulas.
Why Shoe Sizing Is Complicated
Shoe making existed long before mass production, so many regions developed their own measurement and labeling methods. Differences between men's and women's feet, brand lasts, and the fact that two people with the same foot length may prefer different fits all make a single "perfect" conversion impossible. This tool uses foot length as a consistent reference: you measure your foot once, then see the equivalent size in each system. The tables and formulas below are our best interpretation and may differ slightly from other sources or brands.
For the best fit, always try shoes on when possible. Use this converter as a starting point, especially when buying online or converting a size you already know.
Shoe Size Calculation Formulas
Size is derived from foot length. US and UK use length in inches; EU, Japan, and China use length in centimeters. L = foot length below.
U.S. and Canada
- Women's shoe size ≈ 3L − 21
- Men's shoe size ≈ 3L − 22
- Big kid's (5–12) ≈ 3L − 22¾
- Little kid's (0–4) ≈ 3L − 9¾
L = foot length in inches. Sizes increase in half-point increments.
UK / India
- Adult shoe size ≈ 3L − 23
- Big kid's ≈ 3L − 23¾
- Little kid's ≈ 3L − 10¾
L = foot length in inches. Half-point increments.
EU
Shoe size = (3/2)L + 2
L = foot length in centimeters. Whole-point increments.
Japan / Mexico
Shoe size = L
L = foot length in centimeters. Often in half-point increments.
China
Shoe size = 2L − 10
L = foot length in centimeters. Whole-point increments.
Shoe Size Charts
Reference tables by category. Foot length is in inches and cm. Use the converter above for values in between.
Women's shoes
| US/CA | UK/IN | EU | JP/MX | CN | Foot (in) | Foot (cm) |
|---|---|---|---|---|---|---|
| 4 | 2 | 34 | 21 | 32 | 8.3 | 21.2 |
| 4.5 | 2.5 | 34 | 21.5 | 33 | 8.5 | 21.6 |
| 5 | 3 | 35 | 22 | 34 | 8.7 | 22 |
| 5.5 | 3.5 | 36 | 22.5 | 35 | 8.8 | 22.4 |
| 6 | 4 | 36 | 23 | 36 | 9 | 22.9 |
| 6.5 | 4.5 | 37 | 23.5 | 37 | 9.2 | 23.3 |
| 7 | 5 | 38 | 23.5 | 37 | 9.3 | 23.7 |
| 7.5 | 5.5 | 38 | 24 | 38 | 9.5 | 24.1 |
| 8 | 6 | 39 | 24.5 | 39 | 9.7 | 24.6 |
| 8.5 | 6.5 | 39 | 25 | 40 | 9.8 | 25 |
| 9 | 7 | 40 | 25.5 | 41 | 10 | 25.4 |
| 9.5 | 7.5 | 41 | 26 | 42 | 10.2 | 25.8 |
| 10 | 8 | 41 | 26 | 42 | 10.3 | 26.2 |
| 10.5 | 8.5 | 42 | 26.5 | 43 | 10.5 | 26.7 |
| 11 | 9 | 43 | 27 | 44 | 10.7 | 27.1 |
| 11.5 | 9.5 | 43 | 27.5 | 45 | 10.8 | 27.5 |
| 12 | 10 | 44 | 28 | 46 | 11 | 27.9 |
Men's shoes
| US/CA | UK/IN | EU | JP/MX | CN | Foot (in) | Foot (cm) |
|---|---|---|---|---|---|---|
| 6 | 5 | 38 | 23.5 | 37 | 9.3 | 23.7 |
| 6.5 | 5.5 | 38 | 24 | 38 | 9.5 | 24.1 |
| 7 | 6 | 39 | 24.5 | 39 | 9.7 | 24.6 |
| 7.5 | 6.5 | 39 | 25 | 40 | 9.8 | 25 |
| 8 | 7 | 40 | 25.5 | 41 | 10 | 25.4 |
| 8.5 | 7.5 | 41 | 26 | 42 | 10.2 | 25.8 |
| 9 | 8 | 41 | 26 | 42 | 10.3 | 26.2 |
| 9.5 | 8.5 | 42 | 26.5 | 43 | 10.5 | 26.7 |
| 10 | 9 | 43 | 27 | 44 | 10.7 | 27.1 |
| 10.5 | 9.5 | 43 | 27.5 | 45 | 10.8 | 27.5 |
| 11 | 10 | 44 | 28 | 46 | 11 | 27.9 |
| 11.5 | 10.5 | 45 | 28.5 | 47 | 11.2 | 28.4 |
| 12 | 11 | 45 | 29 | 48 | 11.3 | 28.8 |
| 12.5 | 11.5 | 46 | 29 | 48 | 11.5 | 29.2 |
| 13 | 12 | 46 | 29.5 | 49 | 11.7 | 29.6 |
| 13.5 | 12.5 | 47 | 30 | 50 | 11.8 | 30.1 |
| 14 | 13 | 48 | 30.5 | 51 | 12 | 30.5 |
Infant and toddler shoes (age 0–4)
| US/CA | UK/IN | EU | JP/MX | CN | Foot (in) | Foot (cm) |
|---|---|---|---|---|---|---|
| 2 | 1 | 17 | 10 | 10 | 3.9 | 9.9 |
| 2.5 | 1.5 | 18 | 10.5 | 11 | 4.1 | 10.4 |
| 3 | 2 | 18 | 11 | 12 | 4.3 | 10.8 |
| 3.5 | 2.5 | 19 | 11 | 12 | 4.4 | 11.2 |
| 4 | 3 | 19 | 11.5 | 13 | 4.6 | 11.6 |
| 4.5 | 3.5 | 20 | 12 | 14 | 4.8 | 12.1 |
| 5 | 4 | 21 | 12.5 | 15 | 4.9 | 12.5 |
| 5.5 | 4.5 | 21 | 13 | 16 | 5.1 | 12.9 |
| 6 | 5 | 22 | 13.5 | 17 | 5.3 | 13.3 |
| 6.5 | 5.5 | 23 | 14 | 18 | 5.4 | 13.8 |
| 7 | 6 | 23 | 14 | 18 | 5.6 | 14.2 |
| 7.5 | 6.5 | 24 | 14.5 | 19 | 5.8 | 14.6 |
| 8 | 7 | 25 | 15 | 20 | 5.9 | 15 |
| 8.5 | 7.5 | 25 | 15.5 | 21 | 6.1 | 15.5 |
| 9 | 8 | 26 | 16 | 22 | 6.3 | 15.9 |
| 9.5 | 8.5 | 26 | 16.5 | 23 | 6.4 | 16.3 |
| 10 | 9 | 27 | 16.5 | 23 | 6.6 | 16.7 |
Kid's shoes (age 5–12)
| US/CA | UK/IN | EU | JP/MX | CN | Foot (in) | Foot (cm) |
|---|---|---|---|---|---|---|
| 10.5 | 9.5 | 28 | 17 | 24 | 6.8 | 17.1 |
| 11 | 10 | 28 | 17.5 | 25 | 6.9 | 17.6 |
| 11.5 | 10.5 | 29 | 18 | 26 | 7.1 | 18 |
| 12 | 11 | 30 | 18.5 | 27 | 7.3 | 18.4 |
| 12.5 | 11.5 | 30 | 19 | 28 | 7.4 | 18.8 |
| 13 | 12 | 31 | 19.5 | 29 | 7.6 | 19.3 |
| 13.5 | 12.5 | 32 | 19.5 | 29 | 7.8 | 19.7 |
| 1 | 13 | 32 | 20 | 30 | 7.9 | 20.1 |
| 1.5 | 13.5 | 33 | 20.5 | 31 | 8.1 | 20.5 |
| 2 | 1 | 33 | 21 | 32 | 8.3 | 21 |
| 2.5 | 1.5 | 34 | 21.5 | 33 | 8.4 | 21.4 |
| 3 | 2 | 35 | 22 | 34 | 8.6 | 21.8 |
| 3.5 | 2.5 | 35 | 22 | 34 | 8.8 | 22.2 |
| 4 | 3 | 36 | 22.5 | 35 | 8.9 | 22.6 |
| 4.5 | 3.5 | 37 | 23 | 36 | 9.1 | 23.1 |
| 5 | 4 | 37 | 23.5 | 37 | 9.3 | 23.5 |
| 5.5 | 4.5 | 38 | 24 | 38 | 9.4 | 23.9 |
| 6 | 5 | 39 | 24.5 | 39 | 9.6 | 24.3 |
| 6.5 | 5.5 | 39 | 25 | 40 | 9.8 | 24.8 |
| 7 | 6 | 40 | 25 | 40 | 9.9 | 25.2 |
Shoe Size FAQ
? How do I measure my foot for shoe size?
Measure the length from your heel to your longest toe, preferably in the evening when feet are slightly larger. Use a ruler or Brannock device. Fit the shoe to your larger foot if sizes differ. Enter the length in cm or inches above to get equivalent sizes in US, UK, EU, Japan, and China.
? Why do US and UK sizes differ?
US and UK use different zero points and scales. UK adult sizes are typically about 1 size smaller than US men's (e.g. US 10 ≈ UK 9). US women's sizes are usually about 1.5 to 2 sizes above US men's for the same foot length. The formulas (3L − 21 for US women, 3L − 22 for US men, 3L − 23 for UK) reflect these offsets.
? Is EU size the same as US?
No. EU uses the Paris point: size = (3/2)×(foot length in cm) + 2. EU sizes are usually 1–2 numbers higher than US men's for the same foot (e.g. US 9 men ≈ EU 43). This converter shows the exact equivalent for any foot length.
? Why does the same size fit differently by brand?
Shoe size is based on foot length, but fit also depends on the last (the form used to make the shoe), width, and brand. Two brands labeled the same size can fit differently. Use this tool as a starting point and try on or check brand-specific size guides when possible.