Simpson Helmet Sizing Chart Determine your helmet size by measuring your head at a point 1'' above your eyebrow & a point in the back of the head that results in the largest possible measurement. Inches Size Size 20-3/8'' to 21-1/8'' 6-5/8 to 6-3/4 X-Small 21-1/8'' to 22'' 6-7/8 to 7 Small 22'' to 22-3/4'' 7-1/8 to 7-1/4 Medium 22-3/4'' to 23-1/2'' 7-3/8 to 7-1/2 Large 23-1/2'' to 24-3/8'' 7-5/8 to 7-3/4 X-Large 24-3/8'' to 25-1/8'' 7-7/8 to 8 XX-Large
Click here for Simpson Sizing Information http://www.simpsonraceproducts.com/pages/sizechart_motohelmets.htm
