| Giro Sizing Chart | ||
| Size | cm | inches |
| XX Large | 60.5 - 62.5cm | 23¾ - 24½" |
| X Large | 59 - 60.5cm | 23 - 23¾" |
| Large | 57 - 59cm | 22½ - 23" |
| Medium | 55.5 - 57cm | 21¾ - 22½" |
| Small | 53.5 - 55.5cm | 21 - 21¾" |
| X Small | 52 - 53.5cm | 20½ - 21" |
| Youth M/L | 55.5 - 59cm | 22-23¼" |
| Youth XS/S | 52 - 55.5cm | 20½ - 22" |
| Child | 49 - 54cm | 19¼ - 21¼" |
| Use tailor's measuring tape around head (just above eyebrow) for correct sizing | ||