Im a 40DDD(F) and the XL fits me perfectly.  I found this top after having tried on 8+ black swim tops and having zero of them coming even close to fitting right. In desperation, I typed swim bra into Amazon and what do you know. Im obsessed with this top, its so supportive and looks great and is the most comfortable suit Ive ever owned. Its been a month and its holding up great, but Im going to order another in another color just so I have more than one. Love it.