I generally wear a 36DD or 34DDD bra. I ordered a medium and the band size was a very good fit for me (my underbust actually measure 32"). Really liked this bikini top and it is well constructed BUT there just wasn't enough room for my girls. Wore it around the house for a bit and it became uncomfortable. The large might have enough room in the cups but the band will be too big. Unless I alter it. Sigh. Also, the removable cups are annoying to take out and put in but IMO really you could just leave them out and toss them. I hope Athleta will keep trying to accommodate bigger busts in swimwear because otherwise I have to rely on mainstream swimwear bra sized tops which are generally meant for lounging rather than active water pursuits.