Shoei Helmet Sizing

Manufacturer's Suggested Size Chart (Not a guarantee of fit)
SizeInchesCMHat Size
2XS 20(1/8) - 20(1/2) 51-52 6(3/8) - 6(1/2)
XS 20(7/8) - 21(1/4) 53-54 6(5/8) - 6(3/4)
SM 21(5/8) - 22 55-56 6(7/8) - 7
MD 22(1/2) - 22 (7/8) 57-58 7(1/8) - 7(1/4)
LG 23(1/4) - 23(5/8) 59-60 7(3/8) - 7(1/2)
XL 24 - 24(3/8) 61-62 7(5/8) - 7(3/4)
2XL 24(3/4) - 25(1/8) 63-64 7(7/8) - 8
3XL 25(5/8) - 26 65-66 8(1/8) - 8(1/4)

Shoei X-Fourteen Helmet Information

Manufacturer's Suggested Size Chart (Not a guarantee of fit) 
SizeXSSMMDLGXL2XL
Shell SM MD LG XL
EPS Liner SM MD LG XL
Center Pad S13 S9 M9 L9 XL9 XL5
Cheek Pad 39 35 35 35 35 31
Optional Cheek Pad 43/35/31 39/31 39/31 39/31 39/31 39/35