How to choose correct size;   1,You should measure your   foot length  ,and it is   only equal to foot length  !   2,The size standards of   different countries or different manufacture are different,    your foot length is the sole criterion for choosing size.   3,Foot length is not insole length,and it is also not the shoes inside length.   4,Please measure your foot length carefully.And you can do it with the method on the picture.