K2 Helmets Size Chart
Men's
Size
Centimeters
Inches
Small
51-55
20 -21 5/8
Medium
55-59
21 5/8 - 23 1/4
Large
58-61
22 7/8 - 24
Women's
Size
Centimeters
Inches
Small
51-53
20 - 20 7/8
Medium
53-55
20 7/8 - 21 5/8
Large
55-59
21 5/8 - 23 1/4
Junior
Size
Centimeters
Inches
Youth
51-55
20-21 5/8