27=17.2cm     28=17.9cm
29=18.5 cm      30=19.1 cm
31=20.4cm      32=20.1 cm
33=21.6 cm      34=22.2 cm
35=22.7 cm      36=23.2 cm
37=23.7 cm      38=24.2 cm
39=24.8 cm     40=25.3 cm

Please choose size according to foot length.
Please allow 0.3 to 0.6 cm difference because of manual measurement,
We will send you shoes by  size on table.
When you order the shoes, you need to choose according to the CM size.
The comfortable insole size is the foot length + 0.5cm.
For example:  You  foot length is 13 cm, and then you need to order the insole size 13.5 cm.