Shoe Size Conversion

How the sizes are worked out

Every size here is estimated from the length of the foot, which is the only thing the calculator uses. With L as the foot length in inches, the US and Canada women's size is about 3L − 21 and the men's size is about 3L − 22. The UK and India adult size is about 3L − 23. These move in half-size steps. The EU size is 1.5 × L + 2 with L in centimeters, in whole steps. The Japan and Mexico size is the foot length in centimeters, in half steps, and the China size is 2 × L − 10, in whole steps.

Kids and toddlers

Children's sizes use different offsets. For the US and Canada, the little-kid size is about 3L − 9.75 inches, up to size 13.5, after which sizes start again at 1 using 3L − 22.75 for big kids. UK and India sizes are one smaller for little kids, 3L − 10.75, and 3L − 23.75 for big kids. Infants and toddlers use the little-kid formulas. The EU, Japan and China formulas do not change with age.

Out of scope

A size is shown as out of scope when it falls outside the range that exists for that system, such as an adult size below 1 or a big-kid size above US 7. If you enter a size that is outside what a group wears, switch the group to the right age.

Getting a good fit

Shoe size is a complicated subject because there is no global standard. Brands use different lasts, countries use different systems, and most people have feet of slightly different sizes. Measure your feet in the afternoon, standing, from the back of the heel to the end of the longest toe, and measure both feet. Then use the longer one and add a little room for the toes, about a thumb's width. A fitting device such as a Brannock device also measures width and arch length, which the length alone cannot tell you.

Common questions