I'm 5 ' 5" and 132 lbs., 34d and the size m is perfect. i will probably wear a thin, long cami under it as it is slightly see through. it doesn't gape under the arms like some sleeveless items...it fits smoothly. as the other review mentioned, it would be a perfect swim suit cover up. but i'm going to wear it more as a casual, very versatile, perfect for a hot day summer dress!