Size Chart (Apparel) - Giro Helmet
Adult Helmet Chart
| ADULT SUPER FIT SIZE | CIRCUMFERENCE |
| S | 51 - 55 cm |
| M | 55 - 59 cm |
| L | 59 - 63 cm |
| XL | 63 - 65 cm |
Adult Helmet Chart
| ADULT SUPER FIT SIZE | CIRCUMFERENCE |
| S | 51 - 55 cm |
| M | 55 - 59 cm |
| L | 59 - 63 cm |
| XL | 63 - 65 cm |
Adult Universal Helmet Chart
| ADULT UNIVERSAL | CIRCUMFERENCE |
| Women Adult | 50 - 57 cm |
| Unisex | 54 - 61 cm |
| Extra Large | 58 - 65 cm |
Youth Helmet Chart
| YOUTH SIZE | CIRCUMFERENCE |
| XS (Scamp Model) | 45 - 49 cm |
| S (Scamp Model) | 49 - 53 cm |
| XS (Dime Model) | 47 - 51 cm |
| S (Dime Model) | 51 - 55 cm |
| Universal Child | 47 - 54 cm |
| Universal Youth (Ages 5+) | 50 - 57 cm |