Helmet Sizes
Head Circumference Inches
Head Circumference Metric
3XS
17 1/8" - 18"
43.5 - 45.7 cm
2XS
18 1/8" - 19"
46 - 48.3 cm
XS
19 1/8" - 20"
48.6 - 50.8 cm
S
20 1/8" - 21"
51.1 - 53.3 cm
M
21 1/8" - 22"
53.7 - 55.9 cm
L
22 1/8" - 23"
56.2 - 58.4 cm
XL
23 1/8" - 24"
58.7 - 61 cm
2XL
24 1/8" - 25"
61.3 - 63.5 cm
3XL
25 1/8" - 26"
63.8 - 66 cm
4XL
26 1/8" - 27"
66.4 - 68.6 cm