I'm 5'7, 135lbs, usually wear a small or medium top (I'm a bit bigger chested and have a long torso) and ordered the white top in medium. It fits just fine but is SUPER sheer. Like see-through curtain sheer. I love the style, just hesitant about the top even with wearing a tank underneath. Will keep though as I'm starting a new job very soon and don't have time to return/find replacement top