Sizing:
Infant: 0-3 Toddler Shoe Size
Extra Small: 4-6 Toddler Shoe Size
Small: 7-10 Toddler Shoe Size
Medium: 10-13 Toddler/Kids Shoe Size
Large: 1-7 Big Kids/Womens 4-10/Mens 4-8 Shoe Size

Sizes Infant/XXS, Extra Small, Small Medium have logo grips on the bottom of the feet and size large have a stitched logo on the bottom of the feet.