Kids' US shoe sizes climb to 13 and then restart at 1Y for bigger kids — a US 1Y is bigger than a US 13, not smaller. This chart covers both ranges so you can convert either one to EU.
US kids' shoe sizing runs from small toddler sizes up through 13, then restarts as "youth" sizing at 1Y, 2Y, 3Y and up — written with a Y specifically so it isn't confused with the toddler range. A toddler US 13 is an EU 31; the very next size up, US 1Y, is an EU 32 — bigger, despite the smaller-looking number.
Because of that restart, "US size 4" is genuinely ambiguous on its own — it could be a small toddler shoe (EU 20) or a bigger kid's shoe (EU 36+) depending on which range it's from. Always check whether a US kids' size has a Y after it (youth) or not (toddler) before converting.
| US kids (toddler) | EU |
|---|---|
| 4 | 19 |
| 5 | 20 |
| 5.5 | 21 |
| 6.5 | 22 |
| 7.5 | 23 |
| 8 | 24 |
| 9 | 25 |
| 9.5 | 26 |
| 10 | 27 |
| 11 | 28 |
| 11.5 | 29 |
| 12.5 | 30 |
| 13 | 31 |
| US kids (youth) | EU |
|---|---|
| 1Y | 32 |
| 2Y | 33 |
| 3Y | 34 |
| 3.5Y | 35 |
| 4Y | 36 |
| 5Y | 37 |
| 6Y | 38 |
US kids' sizing counts up to 13 for toddlers, then starts over at 1Y for bigger kids — a 1Y is larger than a 13, and the Y marks it as the restarted youth range.
A toddler US 13 is an EU 31 — the last size before the youth range restarts.
A US 1Y is an EU 32 — one EU step larger than a toddler US 13, even though the US number itself dropped back down to 1.