About the size
⚡ RAIJIN – HELMET SIZE GUIDE
Arai • Shoei • Kabuto: Japanese sizing!
🔥 Why a special “Japan Sizing” guide?
The helmets sold on Raijin.store come directly from Japan .
Japan uses a JIS sizing standard, which is different but very precise , and sometimes slightly different from European and American sizes.
👉 Objective: to guarantee you the perfect fit the first time .
⚡ Quick summary
- Arai → slightly wider , EU fit
- Shoei → standard size , US/EU fit
- Kabuto → tighter , sporty cut
- Between two → take the bigger one
🧠 How to measure your head circumference? (Super easy)
To ensure your helmet fits perfectly:
1. Take a tape measure .
2. Measure the head circumference , just above the eyebrows and above the ears.
3. Keep the tape perfectly horizontal .
4. Read the measurement in centimeters → compare with the tables below.
💡 If you are between two sizes = take the larger size.
🥇 ARAI – Sizes Japan → EU / US
Cut: European Oval • Very faithful
| Size JP | Head circumference | EU/US Size |
|---|---|---|
| XS | 53–54 cm | XS |
| S | 55–56 cm | S |
| M | 57–58 cm | M |
| L | 59–60 cm | L |
| XL | 61–62 cm | XL |
| XXL | 63–64 cm | XXL |
Arai notes:
✔ Slightly oval cut → perfect for Europeans
✔ Very stable & very precise
✔ Premium comfort
🥈 SHOEI – Sizes Japan → EU / US
Cut: Intermediate Oval (USA/EU standard)
| Size JP | Head circumference | EU/US Size |
|---|---|---|
| S | 55 cm | S |
| M | 57 cm | M |
| L | 59 cm | L |
| XL | 61 cm | XL |
| XXL | 63 cm | XXL |
Shoei Notes:
✔ Extremely accurate size
✔ The X-Fifteen / Marquez / Motegi regular size
✔ Perfect mix of comfort & support
🥉 KABUTO – Sizes Japan → EU / US
Fit: Slightly tighter
| Size JP | Head circumference | EU/US Size |
|---|---|---|
| S | 55–56 cm | S |
| M | 57–58 cm | M |
| L | 59–60 cm | L |
| XL | 61–62 cm | XL |
| XXL | 63–64 cm | XXL |
Kabuto's Notes:
✔ Tighter fit → holds up very well at high speed
✔ Very lightweight
✔ Ideal for sporty drivers & roadsters
🥊 Quick comparison: which helmet is the smallest size?
| Brand | The fit felt |
|---|---|
| Kabuto | 🔥 The tightest |
| Shoei | ⚡ Standard size |
| Arai | 🌐 Slightly wider (EU oval) |
🎯 Quick recommendations for choosing your size
🇪🇺 Europeans
➡ Take your usual size (Arai & Shoei = perfect)
🇺🇸 Americans
➡ Arai & Shoei = same as US sizes
➡ Kabuto may appear a little tighter
Between two sizes?
➡ Choose the next size up
➡ Especially for Kabuto
🛡️ Raijin advice
A helmet must be:
✔ tight at the beginning
✔ stable when you move your head
✔ No pain in the temples
✔ no pressure points
💬 Need help?
Send us your head circumference → we'll tell you the perfect size in 60 seconds .