Giro Bike Helmets Size Chart
Super Fit
IN
CM
XS
18.5-20"
47-51
S
20-21.75"
51-55
M
21.75-23.25"
55-59
L
23.25-24.75"
59-63
XL
24-25.55"
61-65
Universal Fit
IN
CM
Adult
21.25-24"
54-61
Women
19.75-22.5"
50-57
Youth Fit
IN
CM
S/M
18-19.75"
46-50
M/L
19.75-21.5"
50-54
Toddler
18.75-20.5"
48-52
Child
18.5-21/4"
47-54
Youth
19.7-222.4"
50-57