Below is the size measurement for in sole. (*We advise getting in sole 1.5~2 cm bigger than foot length for extra comfort.Size 25: in sole 16.5cmSize 27: in sole 18cmSize 29: in sole 19.5cmSize 31: in sole 20.5cmSize 33: in sole 21.5cm*e.g. if foot length is 18cm, advise getting size 29 or 31