Note: All measurements are in inches.

Size Underbust  Chest 
S 28-31 36-40 (B-D Cup)
M 32-35 40-45 (B-DD Cup)
L 36-39 45-49 (B-DD Cup)
XL 40-43 48-56 (B-H Cup)
2XL 44-45 52-58 (B-H Cup)
3XL 46-47 53-60 (B-H Cup)