Bell Bike Helmets Size Chart
Universal Sizing
| Size | CM | IN | Hat Size |
| Universal Women's & S/M | 50-57 | 19 5/8"– 22 1/2" | 6 1/4"– 7 1/8" |
| Universal Adult & M/L | 53-60 | 20 7/8"–23 5/8" | 6 5/8"–7 1/2" |
| Universal XL | 58-63 | 22 7/8"– 24 7/8" | 7 1/4"– 7 7/8" |
Traditional Sizing
| Size | CM | Inches | Hat Size |
| Small | 52-56 | 20 1/2"– 22" | 6 1/2"– 7" |
| Medium | 55-59 | 21 5/8"– 23 1/4" | 6 7/8"– 7 3/8" |
| Large | 58-62 | 22 7/8"– 24 3/8" | 7 1/4"– 7 3/4" |