Please choose size based on your foot length. 22cm foot length = US 4.5 size. 22.5cm foot length = US 5 size. 23cm foot length = US 6 size. 23.5cm foot length = US 6.5 size. 24cm foot length = US 7.5 size. 24.5cm foot length = US 8.5 size. 25cm foot length = US 9 size. 25.5cm foot length = US 9.5 size. 26cm foot length = US 10 size. 26.5cm foot length = US 10.5 size. Wide feet and fat feet, please choose one bigger size .