Oakley Size Chart
Measurements below are head circumference. Use a flexible tape measure and wrap it around your head just at the top of the brow and around the temples.
Helmets
| Size | S | M | L |
| Inches | 6¼ - 6¾" | 6 7/8" - 7 7/8" | 7½ - 7 7/8" |
| Centimeters | 51 - 55 | 55 - 59 | 59 - 63 |