Sena 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.
Sena Bike Helmet Size Charts
Sena Smart Road Cycling Helmets
| Model | S | M | L |
|---|---|---|---|
| R1 Smart Cycling Helmet | 50 – 55cm | 55 – 58cm | 58 – 62cm |
| 19⅝” – 21¾” | 21¾” – 22⅞” | 22⅞” – 24½” | |
| R1 Evo Smart Cycling Helmet | 50 – 55cm | 55 – 58cm | 58 – 62cm |
| 19⅝” – 21¾” | 21¾” – 22⅞” | 22⅞” – 24½” | |
| R2 Smart Cycling Helmet | 50 – 55cm | 55 – 58cm | 58 – 62cm |
| 19⅝” – 21¾” | 21¾” – 22⅞” | 22⅞” – 24½” | |
| R2 Evo Smart Cycling Helmet | 50 – 55cm | 55 – 58cm | 58 – 62cm |
| 19⅝” – 21¾” | 21¾” – 22⅞” | 22⅞” – 24½” | |
| RX2 Smart Cycling Helmet | 50 – 55cm | 55 – 58cm | 58 – 62cm |
| 19⅝” – 21¾” | 21¾” – 22⅞” | 22⅞” – 24½” | |
| C1 Smart Cycling Helmet | 54 – 58cm | 58 – 61cm | |
| 21¼” – 22⅞” | 22⅞” – 23¾” |
Sena Smart Hybrid Cycling Helmets
| Model | M | L |
|---|---|---|
| Rumba Multi-Sport Helmet | 54 – 58cm | 58 – 62cm |
| 21¼” – 22⅞” | 22⅞” – 24½” | |
| X1S Smart Cycling Helmet | 55 – 59cm | 59 – 63cm |
| 21¾” – 23⅜” | 23⅜” – 24¾” |
Sena Smart Trail Helmets
| Model | M | L |
|---|---|---|
| M1 Mountain Bike Helmet | 55 – 59cm | 59 – 63cm |
| 21¾” – 23⅜” | 23⅜” – 24¾” | |
| M1 Evo Mountain Bike Helmet | 55 – 59cm | 59 – 63cm |
| 21¾” – 23⅜” | 23⅜” – 24¾” |