The kids foot length 12.5 cm,need to choose the insole length is 13.5 cm. because need to give the socks 1 cm space.
Insole length=Foot length (Heel to toe) + 1.0cm.
Choose Shoe Size 21 = Insole Length 13.5 (cm) / Suitable for Foot Length 12.5 (cm)
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