длина ступни в см. и размеры обуви, нашла в интернете:

9,4 cm = Gr. 16 20,0 cm = Gr. 32
10,0 cm = Gr. 17 20,7 cm = Gr. 33
10,7 cm = Gr. 18 21,3 cm = Gr. 34
11,4 cm = Gr. 19 22,0 cm = Gr. 35
12,0 cm = Gr. 20 22,7 cm = Gr. 36
12,7 cm = Gr. 21 23,3 cm = Gr. 37
13,4 cm = Gr. 22 24,0 cm = Gr. 38
14,0 cm = Gr. 23 24,7 cm = Gr. 39
14,7 cm = Gr. 24 25,3 cm = Gr. 40
15,4 cm = Gr. 25 26,0 cm = Gr. 41
16,0 cm = Gr. 26 26,7 cm = Gr. 42
16,7 cm = Gr. 27 27,3 cm = Gr. 43
17,4 cm = Gr. 28 28,0 cm = Gr. 44
18,0 cm = Gr. 29 28,7 cm = Gr. 45
18,7 cm = Gr. 30 29,3 cm = Gr. 46
19,3 cm = Gr. 31