• for choosing your swimsuit top, you use the bust size size chart for full tops and the CUP/bra size  size chart for bikini tops ie if your bust measurement is 36 inches but your bra size is 32D you'll need a S for a regular swimsuit top and M for bikini top 
  • for choosing your bottoms, your waist measurement is the most important measurement e.g if your waist is 27 inches and your hips are 40 inches you can wear a size S or M bottoms
  • for one pieces your bust is the most important measurement