1. Measurement
Measuring the head is a starting point for the entire sizing procedure. Due to varying shapes, heads that are apparently the same size when measured by a tape may not necessarily fit the same size helmet.
A small metal tape measure, or a cloth tape may be used to make your initial measurement.
The circumference of the head should be measured at a point approximately one inch above the eyebrows in front, and at a point in the back of the head that results in the largest possible measurement. Take several measurements, to make sure you have the largest one.
PLEASE NOTE THAT THIS IS A ROUGH GUIDE AND NOT EXACT. THE SHAPE OF YOUR HEAD IS AS IMPORTANT AS THE MEASUREMENT WHICH MAY AFFECT FINAL FIT!
Size Cross Reference
Motorcycle Helmet Sizing Chart| YOUTH HELMET SIZE | HEAD CIRC. (IN) | HEAD CIRC. (CM) | HAT SIZE |
| Youth SM | 19 1/2" - 20" | 50cm - 51cm | 5 7/8 - 6 1/8 |
| Youth MD | 20" - 20 1/2" | 51cm - 52cm | 6 1/8 - 6 3/8 |
| Youth LG | 20 1/2" - 21" | 52cm - 53cm | 6 3/8 - 6 5/8 |
| ADULT HELMET SIZE | HEAD CIRC. (IN) | HEAD CIRC. (CM) | HAT SIZE |
| XS | 20 7/8" - 21 1/4" | 53cm - 54cm | 6 5/8 - 6 3/4 |
| SM | 21 5/8" - 22" | 55cm - 56cm | 6 7/8 - 7 |
| MD | 22 3/8" - 22 3/4" | 57cm - 58cm | 7 1/8 - 7 1/4 |
| LG | 23 1/4" - 23 5/8" | 59cm - 60cm | 7 3/8 - 7 1/2 |
| XL | 24" - 24 3/8" | 61cm - 62cm | 7 5/8 - 7 3/4 |
| XXL | 24 3/4" - 25 1/4" | 63cm - 64cm | 7 7/8 - 8 |
Auto Helmet Sizing Chart
| ADULT HELMET SIZE | HEAD CIRC. (IN) | HEAD CIRC. (CM) | HAT SIZE |
| XXS | 21 1/4" - 21 5/8 | 54cm - 55cm | 6 3/4 - 6 7/8 |
| XS | 22 | 56cm | 7 |
| SM | 22 3/8" | 57cm | 7 1/8 |
| MD | 22 3/4" - 23 1/8" | 58cm - 59cm | 7 1/4 - 7 3/8 |
| LG | 23 1/2" - 23 7/8" | 60cm - 61cm | 7 1/2 - 7 5/8 |
| XL | 24 1/4" | 62cm | 7 3/4 |
| M3 XTRA 8 | 25 1/8" - 25 1/2" | 64cm - 65cm | 8 |
| M3 XTRA 8 1/4 | 25 7/8" - 26 1/4" | 66cm - 67cm | 8 1/4 |
| M3 XTRA 8 1/2 | 26 3/8" | 68cm | 8 1/2 |