S/M Women| Shoe 5 - 9 | Calf 9in - 13in

L/XL Women| Shoe 9 - 13 | Calf 13in - 16in

2XL/3XL Women| Shoe 11UP | Calf 16in - 20in

US Sizing Guide - Men

S/M Men| Shoe 5 - 9 | Calf 9in - 13in

L/XL Men| Shoe 8 - 13 | Calf 13in - 16in

2XL/3XL Men| Shoe 11UP | Calf 16in - 20in