Kids' Shoe Size Calculator
Children's sizing, with growing room built in.
Calculate children's shoe size from a foot measurement in US, UK and European scales, including how much growing room to allow.
Heel against a wall, mark the longest toe, measure in the evening. Use the larger foot.
Optional. Enter it to get a width letter as well as a length.
US size
10.5
UK 10.0 · EU 28.0 · 17.0 cm
Allow about a centimetre of growing room beyond the longest toe, and remeasure every six to eight weeks under three. More room than that changes how a child walks.
How the Kids' Shoe Size Calculator works
The children's barleycorn scale restarts at its own zero, which is why a child's 13 is followed by an adult 1 rather than a 14. The harder problem is growing room: too little and the shoe is outgrown in weeks, too much and the child walks badly in it. Both are handled here.
Also known as: children's shoe size chart · toddler foot size calculator
How the number is derived
The children's barleycorn scale counts from its own zero — a last of 12 barleycorns rather than the adult 25 — which is why children's sizes run from about a 0 to a 13 and then restart at an adult 1. The step is the same third of an inch; only the starting point changes.
The wearing allowance matters more here than in adult sizing, because it competes with growing room. The allowance is built into the scale; growing room is added on top of it, and about a centimetre beyond the longest toe is the usual figure.
That centimetre is a compromise, not a rule. Too little and the shoe is outgrown inside a month; too much and the foot slides forward, which is what makes children curl their toes to grip and produces the wear pattern that looks like the shoe is too small.
A worked example
A three-year-old measures 170 mm. Adding the allowance gives a 185 mm last, which is 21.8 barleycorns; subtracting the child zero of 12 leaves a UK 9.8, sold as a 10. Adding a centimetre of growing room to the foot measurement instead — 180 mm — would put them at a UK 11.
That single centimetre is a whole size, which is the crux of children's fitting: the growing room and the size step are the same order of magnitude, so a small judgement about one changes the other completely.
Where the answer misleads
Children's feet grow in bursts rather than steadily, so a size that fitted six weeks ago genuinely may not now. Under three, remeasure every six to eight weeks; up to school age, every three months. The measurement is cheap and the alternative is a shoe that has been too small for a month without anyone noticing, because young children rarely complain about it.
Buying two sizes up to make shoes last is a false economy twice over. It changes how a child walks while the shoe is too big, and the shoe is usually worn through before it is grown into, so the extra months never arrive.
The scale also restarts at 13, which trips people up when a child moves into adult sizes. A child's 13 is followed by an adult 1 — a jump in the label with no jump in the foot.
Frequently asked questions
How much growing room should a child's shoe have?
About a centimetre, roughly a thumb's width, between the longest toe and the end of the shoe. Much more than that and the foot slides forward as they walk, which causes the toe-curling that looks like the shoe is too small.
How often should I remeasure?
Every six to eight weeks under three, and every three months or so up to school age. Children's feet grow in bursts rather than steadily, so a size that fit last month genuinely may not now.
Why does the scale restart at adult sizes?
The children's scale counts from a smaller barleycorn zero. It runs out around a 13, and the next size up is a 1 in the adult scale — a jump in the label, not in the foot.
Should I buy a size up to last longer?
Not more than the standard growing room. A shoe that is too long changes how a child walks and wears unevenly, and the saving is smaller than it looks because the shoe is usually worn out before it is grown into.
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