Helmet Size

Inches

Centimeters

Hat Size

X-Small

21.26

54

6 3/4

Small

21.65 - 22.05

55/56

6 7/8 - 7

Medium

22.44 - 22.83

57/58

7 1/8 - 7 1/4

Large

23.23 - 23.62

59/60

7 3/8 - 7 1/2

X-Large

24.02 - 24.48

61/62

7 5/8 - 8