I tried on a size 8 in the store just for fun... (i am a 0 petite) and then decided to take a chance and order my usual size. i was a little worried as many reviews said the dress was small, but it was on back order and decided to wait before ordering a size up. the 0p was actually fine, yes, it is a little hard to zip up, but once on, it is totally fine... not even too snug... but i didn't sit and eat... we shall see. i don't plan on ordering the size up. i think the zipper needed some wiggling