Wrap a tape measure horizontally around your forehead. Select the helmet that is the closest fit to that size. A helmet should fit snug on your head. If it moves while wearing, it is too large. If it is painful to wear, it is too small.
Comment: Had originally ordered an AFX 90 but the fit wasn't quite right, too tight on the forehead. Sent it back to Jafrum and called for advice. They suggested the HJC as not being as round. I ordered and got it faster than expected. It is a real nice helmet. Looks great and fits great. Just need some snow so I can get out and use it....
Long Island New York
HJC CS-R2 Storm Snow Helmet Review
Comment: Fits great, looks great. Bought for snowmobiling and I am happy with the purchase.