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Free sizing tool

Cycling Helmet
Size Chart.

Measure your head circumference to find your recommended helmet size, then check the full youth to XL chart in inches and centimetres below.

Your measurement
Wrap the tape around the widest part of your head, about one inch above your eyebrows and ears, and keep it level. Use the larger of two readings.

A helmet must be snug. If you are between sizes, choose the smaller one and loosen the dial.

Recommended size
M
Fits a 21.7-23.2 in (55-59 cm) head
Your head 22.4 in / 57 cm
Note

This size should sit level and snug. Fine-tune with the rear retention dial.

Size bands differ slightly by brand. Always check the maker's chart, and try the helmet on before you rely on it.

The chart

Cycling helmet size chart

Size Head (in) Head (cm)
XS / Youth 18.9-20.5 48-52
S 20.5-21.7 52-55
M 21.7-23.2 55-59
L 23.2-24.4 59-62
XL 24.4-25.6 62-65

These are typical adult and youth bands. Universal one-size helmets cover roughly 54 to 61 cm with a dial, but a sized helmet matched to your measurement gives a closer, lighter and safer fit.

Want a printable cycling kit size chart?
A one-page helmet, jersey and glove sizing reference is coming soon to our shop.
FAQ

Cycling helmet sizing FAQ

Wrap a soft tape measure around the widest part of your head, about one inch (2 cm) above your eyebrows and ears, keeping it level all the way round. Take the measurement twice and use the larger number. That circumference is exactly what this size chart uses to recommend a helmet size.

A helmet should sit level and low on your forehead, about two finger widths above your eyebrows, and feel snug all the way around without pressure points. When fastened, it should not rock forward, back or side to side. Shake your head with the straps undone: a well-sized helmet stays put.

If your head circumference falls between two sizes, choose the smaller size first and use the helmet retention dial to loosen it slightly. A helmet that is too big cannot be made safe with padding, while a slightly snug one can be dialed out. Only size up if the smaller shell leaves red marks or causes a headache.

Some budget helmets are sold as one universal size, roughly 54 to 61 cm, adjusted with a dial at the back. Mid and high-end helmets come in two or three size bands (S, M, L) for a closer fit and lower weight. For the best fit and protection, a sized helmet that matches your measurement is preferable to a universal one.

Helmet sizing is based on head circumference, which is unisex, so the same chart applies to everyone. Some brands offer womens specific helmets with a rear cradle shaped for a ponytail, but the size bands are identical. Measure your head and match the number regardless of which range you are shopping.

Replace a helmet immediately after any crash or hard impact, even if it looks fine, because the protective foam crushes once and cannot absorb a second hit. Otherwise, most manufacturers recommend replacing a helmet every three to five years as foam, straps and glue degrade with sweat, sunlight and time.