Im 53, 200lbs, 38D-33-43 and ordered a Medium based on other reviews...its perfect.  Keep in mind, the straps aren't adjustable so this will be shorter on taller women.  I took a star off because it is very thin...you can see my bra/cleavage right through the front.  I have a comfy romper shaper thing made by Maidenform Flexees I will be wearing underneath this when I leave the house.  Fingers crossed it holds up in the wash.  So far, so good, though!