Measuring your head with a fabric tape measure around the circumference of your head holding the tape just above your eyebrows and ears. 1" = 25mm
A1/2 Helmet Size Chart
Head
Circumference
Inches 19 19 3/8 19 3/4 20 1/8 20 1/2 20 7/8 21 1/4 21 5/8 22 22 3/8 22 3/4 23 1/4 23 5/8 24 24 3/8
Hat 6 6 1/8 6 1/4 6 3/8 6 1/2 6 5/8 6 3/4 6 7/8 7 7 1/8 7 1/4 7 3/8 7 1/2 7 5/8 7 3/4
CM 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62
Helmet Model Bike Helmets
A1 Y/XS
S M/L XL/XXL
A2 S M/L XL/XXL