You should always start with the dancer's street shoe size, which is what they normally wear on a day-to-day basis. Then, follow the sizing suggestion of the shoe you are ordering under the Sizing tab next to the Description of the item. Please take note, this is only a suggestion and not a guarantee due to the various shapes and sizes of feet. You can always call our Customer Service at 1-800-328-7107 if you need any further assistance.