Tight!
Could not even zip a medium, even though I am typically a size 8 in dresses due to a larger bust. I got one size up (large) and it fits great! I could stand to have the straps taken up about an inch and an inch off the bottom, but unfortunately, I do not have time before the event, with having to wait for the second dress to come in. The color is gorgeous, and I can't wait to wear it!