A helmet that doesn't fit correctly can't protect you properly — and it won't be comfortable enough to wear consistently. Getting your helmet size right is one of the most important steps in the buying process. Here's exactly how to do it.
What You'll Need
- A flexible fabric measuring tape (a tailor's tape)
- A mirror, or a friend to help
- A pen and paper to record your measurement
No fabric tape? Use a piece of string, then measure the string against a ruler.
Step-by-Step: How to Measure Your Head Circumference
- Position the tape — Wrap the measuring tape around the largest part of your head. This is typically about 1 inch (2.5 cm) above your eyebrows and ears, and around the widest part of the back of your skull.
- Keep it level — The tape should be parallel to the ground all the way around. Tilting it up or down will give you an inaccurate reading.
- Snug, not tight — The tape should sit flush against your head without compressing the skin.
- Record the measurement — Note the circumference in both centimeters and inches. Most helmet size charts use centimeters.
- Measure twice — Take the measurement 2–3 times to confirm consistency.
Helmet Size Chart
Use your head circumference to find your helmet size. Sizes can vary slightly between brands, so always check the specific brand's size chart.
| Size | Circumference (cm) | Circumference (inches) |
|---|---|---|
| XS | 53–54 cm | 20.9–21.3" |
| S | 55–56 cm | 21.7–22.0" |
| M | 57–58 cm | 22.4–22.8" |
| L | 59–60 cm | 23.2–23.6" |
| XL | 61–62 cm | 24.0–24.4" |
| 2XL | 63–64 cm | 24.8–25.2" |
| 3XL | 65–66 cm | 25.6–26.0" |
If you fall between sizes, size up for comfort — especially if you plan to wear a balaclava or liner.
Head Shape Matters Too
Head circumference is only part of the equation. Head shape significantly affects helmet fit. The three most common head shapes are:
- Round oval — Nearly equal front-to-back and side-to-side dimensions. Common among Asian riders; many Japanese helmet brands (Shoei, Arai) fit round oval heads well.
- Intermediate oval — Slightly longer front-to-back than side-to-side. The most common head shape globally; most helmets are designed around this shape.
- Long oval — Noticeably longer front-to-back. European brands like Schuberth often accommodate long oval shapes.
To determine your head shape, look straight down at the top of your head in a mirror, or have someone photograph it from above.
How a Properly Fitting Helmet Should Feel
When you put on a correctly sized helmet:
- It should feel snug and even all the way around — no gaps, no pressure points
- The cheek pads should press firmly against your cheeks (they'll break in over time)
- You should not be able to rotate the helmet more than about an inch side-to-side or front-to-back
- The helmet should not rock forward to expose the back of your head
- There should be no "hot spots" — areas of concentrated pressure that cause discomfort
The Roll-Off Test
To check retention, fasten the chin strap and try to roll the helmet forward off your head by pushing up on the rear. A properly fitting helmet should not roll off. If it does, try a smaller size or a different brand with a better shape match.
New Helmet Break-In Period
New helmets feel tighter than they will after break-in. The EPS liner and cheek pads compress slightly with use. A helmet that feels "just right" out of the box may become too loose after a few months of riding. Aim for a fit that feels snug but not painful when new.
Ready to Find Your Size?
Once you have your measurement, use our Helmet Size Chart to find your size, then browse our full helmet collection. Each product page lists the brand's specific size chart so you can confirm your fit before ordering.
Questions about sizing? Our team is here to help you find the perfect fit.
