Ski and Snowboard Helmet Sizing Charts (Adults) Boeri S 51-52 cm M 53-54 cm M/L 55-56 cm L 57-58 cm XL 60-61 cm XXL 62-63 cm XXXL 63+ cm Giro XS 53.53.5 cm S 53.5-55.5 cm M 55.5-57.5 cm L 57-59.cm XL 59-60 cm XXL 60.5-62.5 cm .  . Ovo S 54 cm M 56 cm M/L 58 cm L 60 cm XL 62 cm  .  . Uvex XXS 51-52 cm XS 53-54 cm S 55-56 cm M 57-58 cm L 59-60 cm XL 61-62 cm K2 S 50-51 cm M 52-55 cm L 56-59 cm XL 60-63 cm Saloman S 55-56 cm M 57-58 cm L 59-60 cm XL 61-62 cm Leedom XS 50 cm S 52 cm M 54 cm M/L 56 cm L 58 cm XL 60 cm XXL 62 cm XXXL 64 cm Red/Burton S 55-56 cm M 57-58 cm L 59-60 cm XL 61-62 cm Briko 54 54 cm 56 56 cm 58 58 cm 60 60 cm 60x 62 cm Team Wendy "W" S/M 51-54.cm M/L 54.5-57.5 cm L/XL 57.5-62 cm   Team Wendy "Ripper" Youth 52-54 cm S 54-56 cm M 56-58 cm   Conversion Chart Centimeters Inches  48 18 7/8 49 19 3/8 50 19 5/8  51 20 52 20 1/2 53 20 7/8 54 21 1/4 55 21 5/8 56 22 57 22 3/8 58 22 3/4 59 23 1/4 60 23 5/8 61 24 62 24 3/8