Size Head Circumference (inches) Head Circumference (cm) Hat Size (US)
S 21 ¼ – 21 ⅝ 54 – 55 cm 6 ¾ – 6 ⅞
M 22 – 22 ⅜ 56 – 57 cm 7 – 7 ⅛
L 22 ¾ – 23 ⅛ 58 – 59 cm 7 ¼ – 7 ⅜
XL 23 ½ – 23 ⅞ 60 – 61 cm 7 ½ – 7 ⅝
XXL 24 ¼ – 24 ⅝ 62 – 63 cm 7 ¾ – 7 ⅞