I think it really depends on your bub (not much help). DD was just under 6pds when born....so she was in 00000 foe five weeks, 0000 for three months and 000 for ages.....00 for ages but she is still pretty petite so I got alot of wear out of her clothes.

I know my sisters little girl is 1yr and she is already in 0-1 so really wasnt in anything too long.