I am 5' 6\" and 168 pounds and a 36D cup. I bought a large.I have not tried on a bathing suit in over 20 years that I felt good in. This is it! I took a risk and purchased this suit which is nothing like my typical all black, hide me in the corner, swimsuit. I am so glad I did! Then, the thickness, softness, and combination of 'pulls you in' while just feeling good fabric, was a pleasant surprise. I tried it on and couldn't believe it-I loved it! You can definitely see 'the girls' and some cleavage, but it holds them in much better and more securely than any other bathing suit I have tried on in a long time. I am just so pleasantly surprised and so glad I took a chance on this colorful swimsuit!