Please make sure to confirm the size before purchasing.Not every pair of shoes is in standard sizes.The inner length of the shoes is measured manually, and there may be a reasonable error of about 0.5cm Regarding the selection of children's shoe sizes, please note the following: Most children's shoe sizes are based on manufacturer's standards and do not have a unified standard (different shoes of the same size may have different dimensions). Please measure the foot length. For summer models, it is recommended that foot length + 0.5cm = shoe inner length. For spring/autumn and winter models, it is recommended that foot length + 1cm = shoe inner length (the cm indicated after each size is the shoe's inner length) Size 16: 11.5cm cm, Size 17: 12cm cm, Size 18: 12.5cm cm, Size 19: 13cm cm, Size 20: 13.3 cm, Size 21: 13.5cm cm, Size 22: 14 cm, Size 23: 14.5cm cm, Size 24: 15 cm, Size 25: 15.5cm cm, Size 26: 16 cm, Size 27: 16.5cm cm, Size 28: 17 cm, Size 29: 17.5cm cm, Size 30: 18 cm centimeter