Size Charts for K2 Helmets
| Size | Circumference | Hat Size |
| X-Small | 48-51cm | - |
| Small/Youth | 52-55cm | 6 3/4 - 6 7/8 |
| Medium | 56-59cm | 7 - 7 3/8 |
| Large/X-Large | 60-62cm | 7 1/2 - 7 3/4 |
| Size | Circumference | Hat Size |
| X-Small | 48-51cm | - |
| Small/Youth | 52-55cm | 6 3/4 - 6 7/8 |
| Medium | 56-59cm | 7 - 7 3/8 |
| Large/X-Large | 60-62cm | 7 1/2 - 7 3/4 |