Size 3C: the kids’ shoe size explained
A size 3C fits a foot of 10.4 to 10.8 cm (4.08 to 4.25 in): UK 2.5–3 and EU 18–18.5 by the standard size tables, a toddler size.
The median child’s foot reaches the middle of a 3C at about 10 months and stays in it for about 2 months, in the US Consumer Product Safety Commission’s survey of children.
Where 3C sits
After 3C: the next sizes
The next size, 3.5C, fits 4.3 mm more foot, up to 11.2 cm. Around the age a 3C is outgrown the median child’s foot grows about 2.9 mm a month, so it fills a 3.5C about 1 month later.
| Size | Foot (cm) | UK | EU | Outgrown at |
|---|---|---|---|---|
| 3C (this size) | 10.4–10.8 | 2.5–3 | 18–18.5 | about 11 months |
| 3.5C | 10.8–11.2 | 3–3.5 | 18.5–19 | about 13 months |
| 4C | 11.2–11.6 | 3.5–4 | 19–19.5 | about 14 months |
Outgrown at: when the median child’s foot reaches the top of the size, girls and boys together. Half of children get there sooner.
What 9 brands print for a 3C
On the brands’ own charts a 3C is for a foot of up to 9.0 cm (Under Armour) to 10.8 cm (UGG); the standard is 10.8 cm. Check the brand’s chart before you buy.
| Brand | Prints | UK | EU | Foot up to |
|---|---|---|---|---|
| Under Armour size chart (opens the brand’s site) | 3K | 2.5 | 18.5 | 9.0 cm |
| adidas size chart (opens the brand’s site) | 3k | 2k | 18 | 9.8 cm |
| Vans size chart (opens the brand’s site) | 3C | 2.5 | 18 | 10.0 cm |
| Crocs size chart (opens the brand’s site) | C3 | 3 | 18-19 | 10.7 cm |
| Jordan size chart (opens the brand’s site) | 3C | 2.5 | 18.5 | 10.8 cm |
| Nike size chart (opens the brand’s site) | 3C | 2.5 | 18.5 | 10.8 cm |
| UGG size chart (opens the brand’s site) | 3T | 2.5 | 18.5 | 10.8 cm |
| Converse size chart (opens the brand’s site) | 3C | 3 | 19 | — |
| Liberty size chart (opens the brand’s site) | 3C | 2C | 18 | — |
Each brand’s own kids’ chart, linked, as it prints the size; “—” where the chart has no such column. Brands that don’t print foot lengths are listed last. Not affiliated with any brand.
Convert another kids’ size
3C in every system
| System | 3C |
|---|---|
| Foot length (cm) | 10.4–10.8 |
| Foot length (in) | 4.08–4.25 |
| UK | 2.5–3 |
| EU | 18–18.5 |
| Japan (cm) | 10.5–11 |
| Mondopoint (mm) | 105–110 |
From the standard size tables; where the foot range spans more than one size, the first and last are shown.
Size tables checked 2026-10-23; ages from the CPSC children’s survey (Snyder et al., 1977, via NIST AnthroKids), median of girls and boys; brand sizes from each brand’s own chart, linked above. An estimate to help you choose: fit varies by brand and model. Not medical advice.