I am 5'4, 130lbs and 36A and I workout at a crossfit gym all the time, so I have an athletic build. My normal dress size is a small-4/6, depends on how it is made and the material. This dress is beautiful in the royal blue and the material in thick and great quality! Without a doubt this dress is tight in any size you pick, because it is supposed to be! I ordered it in a Large after reading all the reviews and it fits me great with a strapless bra. I ordered it in the Large because I want to look classy, not trashy! I hate when women try to fit in the wrong size dress, they must not realize that if it is too small on them, they look so much more bigger then if they would have worn the correct size. I love this dress and will probably get it in another color too. By the way, if you don't have a flat stomach, start doing crunches now because this dress will show any flaw you have!