Size Charts for Pro-Tec Helmets
Senior
| US Size | Centimeters | Inches |
| Small | 53 - 54 | 20 7/8 - 21 1/4 |
| Medium | 55 - 56 | 21 5/8 - 22 |
| Large | 57 - 58 | 22 1/2 - 22 7/8 |
| X-Large | 59 - 60 | 23 1/4 - 23 5/8 |
| XX-Large | 61 - 62 | 24 - 24 1/2 |
Junior
| US Size | Centimeters | Inches |
| Junior | 49 - 54 | 19 1/4 - 21 1/4 |
| Small | 51 - 52 | 20 - 20 1/2 |
| Medium | 53 - 54 | 20 7/8 - 21 1/4 |