I wasn't sure what size to order so I contacted their customer service and was told I should get a small. I ordered the small and the fit is surprisingly good. I am 5'2" and 110 lbs and normally wear a dress size 4. The small size of this costume is just slightly too long and so are the sleeves a bit but otherwise it fits. The costume comes with 5 of the little round rank pins so you can choose which rank you want to be. I'm looking forward to wearing this on Halloween.