I saw this dress and fell in love, and I really like Erin dresses, but the length was weird (it hit right at my knee) and the dress itself was a little boxy. I should have gone with the 4, I think that would have made it a little shorter on me and would have fit better through the middle, but the dress itself was beautifully made. I still really love this designer, but wore my back-up dress instead! I would say rent your normal size, plus maybe a size smaller to have a better fit....