Choosing the Correct Helmet Size

Helmet fit is critical to helmet protective performance. The correct helmet size can only be checked and confirmed by physically fitting the helmet to the user. Always try the helmet on in a store, before purchasing it, to be sure you are purchasing the correct sized helmet for you.

Head Measurement Instructions

Wrap a flexible tape measure around your head approximately one inch above the eyebrows and ears. Use this measurement to find your helmet size in the chart to the right.

Helmet Sizing Information

To achieve proper helmet fitment, begin by finding your head circumference size using the method described. Remember that the helmet size you choose should fit around the crown of your head comfortably with no pressure points. The cheekpads should fit firmly around your face. Once your chin strap is fastened, grab the chin bar of the helmet and move it side to side. Your cheeks should move with the helmet, which should not slide across your face. Different thickness cheekpads can be purchased to obtain the best fit.

Head Circumference Measurement (HCM)

The HCM should be a starting point only in determining your helmet size. Determining the best possible fit should be from actual test fittings of Arai’s various interior fit packages. Changes and updates can affect the standard pad thickness supplied with your helmet.

Helmet Shape

Intermediate Oval

Arai Helmet Size Chart

Defiant-X / Regent-X — Interior Lining Thickness

	HCM (cm)	Lining Code	12 mm	10 mm	7 mm	5 mm
XS	53 - 54	I		⭘	⬤
S	55 - 56	II		⭘	⬤	⭘
M	57 - 58	III	⭘	⬤	⭘	⭘
L	59 - 60	III	⭘	⭘	⬤	⭘
XL	61 - 62	IV		⭘	⬤	⭘
2XL	63 - 64	V		⭘	⬤

Standard ⬤ | Optional ⭘

Arai Helmet Size Chart

Defiant-X / Regent-X — Cheek Pad Thickness

	Thicker (mm)	Standard (mm)	Thinner (mm)
XS	30	25	20
S	30	25	20
M	30	25	20
L	25	20	15
XL	25	20	15
2XL	20	15	-