Bieffe Motorcycle Helmets Size Chart
by Brockton
Cycle
| Size | Centimeter | Inches | Hat size |
| XSm | 54-55 | 20 3/4 - 21 1/8 | 6 1/2 - 6 3/4 |
| Sm | 56-57 | 21 5/8 - 22 | 6 7/8 - 7 |
| Md | 58-59 | 22 3/8 - 22 7/8 | 7 1/8 - 7 1/4 |
| Lg | 60-61 | 23 1/4 - 23 5/8 | 7 3/8 - 7 1/2 |
| XL | 62-63 | 23 7/8 - 24 3/8 | 7 5/8 - 7 1/2 |
| XXL | 64-65 | 24 3/4 - 25 1/8 | 7 7/8 - 8 |