It depends on the height of baby and size of feet. My son got his first pair of shoes at 8 mos, size 2. But he is average height. My nephew was a size three at 8 months, and he is tall. My son is 29 1/4 inches at 1yr and wearing size 3, with room to grow. Size 2 is too small for him only because his feet are chubby, which is typical for babies. So I'd say 6 months to maybe 10mos if baby is average height?? I'm sorry I can't be more help. :(