Children's Shoe Size Calculator by Age
Estimate a child's shoe size from their age or, more accurately, their measured foot length — with US, UK and EU sizes and a reminder of how often to check.
Children's feet grow fast and sizing is best done by measured foot length, because growth varies a lot between children. Use age only as a rough starting point. For the most reliable result, measure the longest toe to heel in centimetres and enter it below.
Children's foot length to shoe size (approximate)
Brands vary, so treat this as a starting point and always confirm fit in person. The sizes below are typical for a measured heel-to-longest-toe length; most children's shoes are designed to be bought with a little growing room already factored into the fitted size.
| Foot length | US (kids) | UK (kids) | EU | Typical age* |
|---|---|---|---|---|
| 12 cm | 4.5C | 3.5 | 20 | 12–18 mo |
| 13 cm | 6C | 5 | 22 | ~2 yr |
| 14 cm | 7C | 6.5 | 23–24 | ~2–3 yr |
| 15 cm | 8.5C | 8 | 25–26 | ~3–4 yr |
| 16 cm | 9.5C | 9 | 27 | ~4–5 yr |
| 17 cm | 11C | 10 | 28–29 | ~5–6 yr |
| 18 cm | 12C | 11 | 30 | ~6–7 yr |
| 19 cm | 13.5C | 13 | 31–32 | ~7–8 yr |
| 20 cm | 1.5Y | 1 | 33 | ~8–9 yr |
| 21 cm | 2.5Y | 2 | 34–35 | ~9–10 yr |
*Age is the least reliable guide — two children of the same age can differ by several sizes. Always size by measured length where you can.
How fast children's feet grow
Young feet grow in spurts, which is why a pair that fit at the start of a season can pinch within weeks. As a rough guide:
- Up to age 3: feet can grow around two shoe sizes a year — re-measure every 6–8 weeks.
- Ages 3–6: roughly one size every few months — re-measure every 8–12 weeks.
- Ages 7–11: growth slows a little — check every 3–4 months.
How to measure a child's foot at home
- Measure at the end of the day, when feet are at their largest, with the socks they'll wear in the shoe.
- Have the child stand on a sheet of paper against a wall so their full weight spreads the foot.
- Mark the heel and the tip of the longest toe (not always the big toe), then measure between the marks.
- Do both feet and size to the larger one — most people have a slightly bigger foot on one side.
Fit check in the shop: leave about a thumb's width (1–1.5 cm) of growing room beyond the longest toe, make sure the widest part of the foot sits at the widest part of the shoe, and watch for red marks or curled toes when the shoes come off — both are signs they're already too small.
If a child consistently skips sizes, complains of foot pain, walks heavily on the inner edge, or in-toes markedly, mention it to a GP or podiatrist rather than just sizing up.
Frequently asked questions
- How often should I measure my child's feet?
- Toddlers and young children may need a re-check every 6 to 8 weeks; school-age children roughly every 3 months. Re-measure sooner if shoes seem tight.
- How much growing room should kids' shoes have?
- About a thumb's width (roughly 1 to 1.5 cm) between the longest toe and the shoe end — enough to grow into without being so loose they trip.
- Is age a reliable way to size children's shoes?
- No. Age gives only a rough range. Two children of the same age can differ by several sizes, so measured length is far more accurate.
About this tool
This estimator maps foot length to standard child shoe sizes, or gives a typical range from age when no measurement is available. It runs in your browser. Always confirm fit in the shop with both shoes on and the child standing, and allow growing room.