O'neill Swimwear Sizing
O'neill Size US Size Bust (inches) Waist (inches) Hip (inches) Cup
XS 00-0 29.5-31 21.5-23 23-23 A/B
S 1-3 32-33 24-25 34-35 A/B/C
M 5-7 34-35 26-27 36-37 A/B/C
L 9-11 36-37.5 28-29.5 38-39.5 B/C
XL 13 39 31 41 B/C
See our complete Lingerie Fitting Guide here.