US Size EU Size UK Size Inches cm Approximate Age  
Infant
0
16
0
3     
7 5/8
 0-12 Months
1 16 0.5 3  1/3 8 1/2
2 17 1 3  2/3 9 1/3
3 18 2 4      10 1/6
3.5 19 2.5 4  1/6 10 3/5
Toddler 4 19 3 4  1/3 11    1-4 Years
4.5 20 3.5 4  1/2 11 3/7
5 20 4 4  2/3 11 6/7
5.5 21 4.5 4  5/6 12 2/7
6 22 5 5      12 2/3
6.5 22 5.5 5  1/6 13 1/8
7 23 6 5  1/3 13 5/9
7.5 23 6.5 5  1/2 14   
8 24 7 5  2/3 14 2/5
8.5 25 7.5 5  5/6 14 4/5
9 25 8 6      15 1/4
9.5 26 8.5 6  1/6 15 2/3
10 27 9 6  1/3 16   
Little Kid 10.5 27 9.5 6 1/2 16 1/2 4-8 Years
11 28 10 6 2/3 17   
11.5 29 10.5 6 5/6 17 1/3
12 30 11 7    17 7/9
12.5 30 11.5 7 1/6 18 1/5
13 31 12 7 1/3 18 5/8
13.5 31 12.5 7 1/2 19   
1 32 13 7 2/3 19 1/2
1.5 33 14 7 5/6 19 8/9
2 34 1 8    20 1/3
2.5 34 1.5 8 1/6 20 3/4
3 35 2 8 1/3 21 1/6
  Women's Sizes
Big Kid 3.5 35 2.5 8 1/2 21 3/5 8-12 Years
5
4 36 3 8 2/3 22   
5.5
4.5 36 3.5 8 5/6 22 3/7
6
5 37 4 9    22 6/7
6.5
5.5 37 4.5 9 1/6 23 2/7
7
6 38 5 9 1/3 23 5/7
7.5
6.5 38 5.5 9 1/2 24 1/8
8
7 39 6 9 2/3 24 5/9
8.5
7.5 39 6.5 9 5/6 25   
9
8 40 7 10    25 2/5
9.5
8.5 40 7.5 10 1/6 25 5/6
10
9 41 8 10 1/3 26 1/4