Adult Sizing
| Size US | Size EU | Size |
| 5 | 36 | XS |
| 6 | 37-38 | XS |
| 7 | 39 | S |
| 8 | 40 | S |
| 9 | 41-42 | M |
| 10 | 43 | M |
| 11 | 44 | L |
| 12 | 45 | L |
| 13 | 46 | XL |
| 14 | 47-48 | XL |
Junior Sizing
| Size | Size EU | Size US |
| XS | 26-27 | 8-9C |
| S | 28-29 | 10-11C |
| M | 30-31 | 12-13C |
| L | 32-33 | 1-2 |
| XL | 34-35 | 3-4 |
O'Neill Size Chart for Neoprene Boots
