7iDP Bike Helmet Size Chart
1. Achieve the perfect fit by measuring your head circumference correctly.
2. Watch the video below to see how to measure your head correctly.
3. VIDEO: How To Measure For A Bike Helmet
4. On the chart below, find the helmet model that you are interested in, then find your head measurement to see which size you need.
7iDP Bike Helmet Size Charts
7iDP Mountain Bike Helmets Standard Sizing
| Model | Youth Medium | Youth Large | X-Small | Small | Medium | Large | X-Large | XX-Large |
|---|---|---|---|---|---|---|---|---|
| M1 Helmet | 48 – 50cm | 50 – 52cm | 53 – 54cm | 55 – 56cm | 57 – 58cm | 59 – 60cm | 61 – 62cm | |
| 18.8″ – 19.6″ | 19.6″ – 20.5″ | 20.75″ – 21.25″ | 21.5″ – 22″ | 22.5″ – 22.75″ | 23.5″ – 23.75″ | 24″ – 24.25″ | ||
| Project 23 ABS | 53 – 54cm | 55 – 56cm | 57 – 58cm | 59 – 60cm | 61 – 62cm | 63 – 64cm | ||
| 20.75″ – 21.25″ | 21.5″ – 22″ | 22.5″ – 22.75″ | 23.5″ – 23.75″ | 24″ – 24.25″ | 24.8″ – 25.2″ | |||
| Project 23 Carbon | 53 – 54cm | 55 – 56cm | 57 – 58cm | 59 – 60cm | 61 – 62cm | 63 – 64cm | ||
| 20.75″ – 21.25″ | 21.5″ – 22″ | 22.5″ – 22.75″ | 23.5″ – 23.75″ | 24″ – 24.25″ | 24.8″ – 25.2″ | |||
| Project 23 Fiberglass | 53 – 54cm | 55 – 56cm | 57 – 58cm | 59 – 60cm | 61 – 62cm | 63 – 64cm | ||
| 20.75″ – 21.25″ | 21.5″ – 22″ | 22.5″ – 22.75″ | 23.5″ – 23.75″ | 24″ – 24.25″ | 24.8″ – 25.2″ |
7iDP Mountain Bike Helmets Sizing #2
| Model | X-Small / Small | Medium / Large | X-Large / 2X-Large |
|---|---|---|---|
| M2 Helmet | 52 – 55cm | 56 – 59cm | 60 – 63cm |
| 20.5″ – 21.75″ | 22″ – 23.25″ | 23.75″ – 25″ |
7iDP Mountain Bike Helmets Sizing #3
| Model | Small / Medium | Large / X-Large |
|---|---|---|
| M5 Helmet | 54 – 58cm | 58 – 62cm |
| 21.25″ – 23″ | 23″ – 24.5″ |