HJC Adult Helmets Size Chart

FG-17 Mamba Helmet
Helmets
Size Hat Size Inches
X-Small 6 3/4 - 6 7/8 21 1/4 - 21 5/8
Small 6 7/8 - 7 21 5/8 - 22
Medium 7 1/8 - 7 1/4 22 1/2 - 22 7/8
Large 7 1/4 - 7 3/8 22 7/8 - 23 1/4
X-Large 7 1/2 - 7 5/8 23 5/8 - 24
2X-Large 7 3/4 - 7 7/8 24 3/8 - 24 3/4
3X-Large 8 - 8 1/8 25 1/4 - 25 5/8

Sizing information is provided by the manufacturer and does not guarantee a perfect fit. Please use this chart as a guide only.