This is my first time ordering a formal dress from FN and I'm not a dressy person so I really wasn't sure my size but the size chart would have me in a large (38-30-42.5) however I ordered the S, M, and L just in case and the stretch is stretching so I very EASILY fit in the small so I'm marking this as "runs large". I did need a bit of help getting the zipper up the last lil half inch once it was on which might not have been necessary in a medium which I probably could have pulled all the way on without help (I pulled the small on just fine until trying to get it over my butt then I had to unzip it just a tiny bit) but I tried the small first hoping for extra support in the boobs which it did give. Mind you, I had an unpadded spaghetti strap bra on but there's some hard V shaped thing inside the dress itself at the bust that keeps the bra part up all in its own so a bra is not needed but a strapless one could be worn for extra cleavage. Gorgeous dress, plenty stretch, not too bad on extra length dragging the ground (I'm 5'2 and with house slippers on it wasn't that bad, with heels on it would be exactly floor length or maybe ankle length on me), and very comfortable. You'll def be able to dance or just sit pretty in this. Well done FN!