Disney costumes run tiny.
During my first trip to the costume room, my supervisor warned me that I should check out a costume two sizes bigger than I'd normally wear, and he was right. Talk about a blow to your ego. He said it was something like the sizing of the costumes followed the sizing of when the park first opened in the '70s, which is smaller than how current sizing works. As a part-time cast member, I was also only allowed to check out three costumes at a time, and every piece of each costume was required as long as I was on stage — including a horrible hat and bow tie.