*These charts are for reference only. Fit may vary depending on the construction, materials and manufacturer.
| US | Inches | CM |
| Infant US 2 | 3 7/8 | 10 |
| Infant US 2.5 | 4 1/4 | 10.7 |
| Toddler US 3.5 | 4 3/4 | 11.9 |
| Toddler US 5 | 5 1/4 | 13.2 |
| Toddler US 6 | 5 3/8 | 13.8 |
| Toddler US 7 | 5 7/8 | 14.8 |
| Toddler US 8 | 6 1/8 | 15.7 |
| Little kid US 9.5 | 6 3/4 | 17 |
| Little kid US 10.5 | 6 7/8 | 17.6 |
| Little kid US 12 | 7 1/2 | 18.9 |
| Little kid US 13 | 7 3/4 | 19.9 |
| Little kid US 13.5 | 8 1/4 | 20.8 |
| Big kid US 1.5 | 8 1/2 | 21.5 |
| Big kid US 2.5 | 8 7/8 | 22.4 |