For reference I'm 5'6" around 110 pounds. I ordered a small and it fit perfectly. I love the short style swim suits and this one looks more sporty. I worn it to the beach and didn't have any trouble with the shorts riding up or anything. The 2 complaints I do have is the straps and the coordinating tank. First the straps; I ask my husband to tighten the top because it felt loose. He said the straps were not easy to tighten. Once I got it where the top felt comfortable, the other 3 straps just flopped down my arms. Very unflattering and sloppy looking. So, lossened straps back some, now the top doesn't feel as comfortable but I can manage, however the other straps still hang loose. Second, the tank top; (which was one of the main reasons I decided on this particular suit) is way big on me. It does not fit snug like shown in the picture. The neck line hangs down way lower than I like and it's very baggy around my waist. Even with these 2 issues I'm overall happy with my purchase and will definitely be wearing this suit on vacation this summer.