| International size | X-Lite | AGV |
| XS | 55 | 53-54 |
| S | 56 | 55-56 |
| M | 58 | MS 57, ML 58 |
| L | 60 | 59-60 |
| XL | 62 | 61-62 |
| XXL | 64 | 63-64 |
| XXXL | 65 | N/A |
| Size label indication | Head circumference (cm) | North America |
| DOT/ Snell | ||
| XS | 53-54 | XS 6 1/2 - 6 5/8 (53-54cm) |
| S | 55-56 | S 6 3/4 - 6 7/8 (55-56cm) |
| M | 57-58 | M 6 7 - 7 1/8 (57-58cm) |
| L | 59-60 | L 7 1/4 - 7 3/8 (59-60cm) |
| XL | 61-62 | XL 7 1/2 - 7 3/8 (61-62cm) |
| XXL | 63-64 | XXL 7 3/4 - 7 7/8 (63-64cm) |
