| Size USA | Cm. | Inch | Age | Size EU |
| 0 | 10 | 3.9 | 0-3 month | 15 |
| 1 | 10.6 | 4.2 | 3-6 month | 16 |
| 2 | 11.3 | 4.6 | 6-9 month | 17 |
| 3 | 12 | 4.75 | 9-12 month | 18 |
| 4 | 12.6 | 5 | 12-18 month | 19 |
| 4.5 | 13.3 | 5.25 | 18-24 month | 20 |
| 5 | 14 | 5.5 | 2 years | 21 |
| 6 | 14.6 | 5.75 | 3 years | 22 |
| 7 | 15.6 | 6.15 | 4 years | 23 |
| 8 | 15.8 | 6.25 | 5 years | 24 |
| 9 | 16.5 | 6.5 | 6 years | 25 |