| Motorcycle Helmet Sizing Chart | |||
| Adult Size | CM | Hat Size | Inches |
| XXSmall | 51-52 | 6 3/8 - 6 1/2 | 20 - 20.5 |
| XSmall | 53-54 | 6 5/8 - 6 3/4 | 20.87 - 21.26 |
| Small | 55-56 | 6 7/8 - 7 | 21.65 - 22.05 |
| Medium | 57-58 | 7 1/8 - 7 1/4 | 22.44 -22.83 |
| Large | 59-60 | 7 3/8 - 7 1/2 | 23.23 - 23.62 |
| XLarge | 61-62 | 7 5/8 - 7 3/4 | 24.02 - 24.41 |
| 2XLarge | 63-64 | 7 7/8 - 8 | 24.80 - 25.20 |
| 3XLarge | 65-66 | 8 1/8 - 8 1/4 | 25.60 - 26.00 |
| 4XLarge | 67-68 | 8 3/8 - 8 1/2 | 26.40 - 26.80 |
| 5XLarge | 69-70 | 8 5/8 - 8 3/4 | 27 - 27.50 |
| Youth Helmet Sizing Chart | ||
| Youth Size | CM | Inches |
| Small | 49 - 50 | 19.15 - 19.50 |
| Medium | 51 - 52 | 20.10 - 20.45 |
| Large | 53 -54 | 20.87 - 21.26 |