When trying to decide between two sizes, choose the larger size for a better fit.

SizeChestWaistHipsHeightWeight
Small (4-6)26''23''27''39''-48''34-44 lbs.
Medium (8-10)29''26''30.5''49-53''57-70 lbs.
Large (12-14)32''28''33''56-60''91-105 lbs.
XL (14-16)33''29''34.5''60-62''105-118 lbs.