Size Chart(Unit:CM/Inch): Size: 21 Insole Length: 13.5CM/5.3" Recommended Age: 12-18 Months EU: 22.5 UK: 5.5 US: 6.5 Suitable For: Toddler Size: 22 Insole Length: 14CM/5.5" Recommended Age: 18-24 Months EU: 23 UK: 6 US: 7 Suitable For: Toddler Size: 23 Insole Length: 14.5CM/5.7" Recommended Age: 2-2.5 Years EU: 24 UK: 7 US: 8 Suitable For: Toddler Size: 24 Insole Length: 15CM/5.9" Recommended Age: 2.5-3 Years EU: 25 UK: 7.5 US: 8.5 Suitable For: Toddler Size: 25 Insole Length: 15.5CM/6.1" Recommended Age: 3-3.5 Years EU: 26 UK: 8 US: 9 Suitable For: Toddler Size: 26 Insole Length: 16CM/6.3" Recommended Age: 3.5-4 Years EU: 26.5 UK: 8.5 US: 9.5 Suitable For: Little Kids Size: 27 Insole Length: 16.5CM/6.5" Recommended Age: 4-4.5 Years EU: 27 UK: 9 US: 10 Suitable For: Little Kids Size: 28 Insole Length: 17CM/6.7" Recommended Age: 4.5-5 Years EU: 28 UK: 10 US: 11 Suitable For: Little Kids Size: 29 Insole Length: 17.5CM/6.9" Recommended Age: 5-5.5 Years EU: 28.5 UK: 10.5 US: 11.5 Suitable For: Little Kids Size: 30 Insole Length: 18CM/7.1" Recommended Age: 5.5-6 Years EU: 29 UK: 11 US: 12 Suitable For: Little Kids Size: 31 Insole Length: 18.5CM/7.3" Recommended Age: 6.5-7 Years EU: 30 UK: 11.5 US: 12.5 Suitable For: Little Kids Size: 32 Insole Length: 19CM/7.5" Recommended Age: 7.5-8 Years EU: 31 UK: 12 US: 13 Suitable For: Little Kids Size: 33 Insole Length: 19.5CM/7.7" Recommended Age: 8.5-9 Years EU: 32 UK: 12.5 US: 13.5 Suitable For: Little Kids Size: 34 Insole Length: 20CM/7.9" Recommended Age: 9-9.5 Years EU: 33 UK: 13 US: 1 Suitable For: Big Kids Size: 35 Insole Length: 20.5CM/8.1” Recommended Age: 9.5-10 Years EU: 33.5 UK: 13.5 US: 1.5 Suitable For: Big Kids Size: 36 Insole Length: 21CM/8.3" Recommended Age: 10-11 Years EU: 34 UK: 14 US: 2 Suitable For: Big Kids