Love this dress.  I put a petticoat underneath it for some extra fluff and it was perfect.  I actually wore it as a dance costume for a 50's themed recital but I will be wearing this out with a cute pair of pumps for sure.  Fabric doesn't really stretch.  Definitely go by your top size.  Any dress that is fitted through the hips I'm usually a large, but because this cuts right above your hipline, I was a medium.  I actually bought a large first and had to exchange it.  (Chest I am a 36 B for reference)