If you are normally a size S in women's we recommend you go down a size.  

WOMENS UNISEX XXS XS S M L XL XXL 3XL
AUSTRALIA & NEW ZEALAND 6 8 10 12 14 16 18 20
EUROPE 32 34 36 38 40 42 44 46
JAPAN XS S M L LL XXL 4L 5L
KOREA 44 55 66 77 88 99 111 122
US 2 4 6 8 10 12 12 16
MENS UNISEX XXS XS S M L XL XXL 3XL
AUSTRALIA & NEW ZEALAND 30 32 34-36 38-40 42-44 46 48 50
EUROPE 30 32 34 36 38 40 42 44
JAPAN 0 1 2 3 4 5 6
KOREA 85 90 95 100 105 110 115 120
US 00 0 2 4 6 8 10 11
CHEST FIT (INCHES) 32-34" 33-35" 36-38" 39-41" 42-44" 45-47" 48-50" 50+
CHEST FIT (CM) 84-89 91-97 88-104 107-112 114-119 122-127 130+
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