I ordered a medium and a large since most reviews said it runs small. I'm 5'7", 128 lbs, 34 C bra size, and usually wear medium. The medium was a little snug, but the large one had just way too much extra fabric at the torso area, so I will return that one and decided to keep the medium. I am a mom of 2, so I feel more comfortable with one-piece swimsuits, but also want something sexy and flattering, and this worked so well. You can't beat the price either. I'm happy with my purchase.