How should a bike helmet fit?

Snug and level, about two finger widths above the eyebrows, with no rocking. Tighten the dial so it stays put before you buckle the strap.

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What size bike helmet do I need?

Bike helmets are sized by head circumference. A correct helmet sits level, two finger widths above your eyebrows, and does not rock when you shake your head.

Size finder — enter your head circumference (cm)

Enter your head circumference to see your recommended size.

Bike helmet size chart

Your head circumference	Recommended size
46 to 50 cm head	Toddler / XS
50 to 54 cm head	Small (kids / small adult)
54 to 58 cm head	Medium Most common adult size.
58 to 61 cm head	Large
61 to 64 cm head	X-Large
64 cm and up head	XXL

How to measure

Wrap a soft tape around your head about 2 cm above the eyebrows.
Keep the tape level all the way around.
Match the cm to the brand size band.

What changes your size

Between sizes	Size down if the dial retention system can expand to fit.
Thick hair	Measure with hair as you normally wear it.

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FAQ

How should a bike helmet fit?: Snug and level, about two finger widths above the eyebrows, with no rocking. Tighten the dial so it stays put before you buckle the strap.