I thunk I switched when my son was about 20-22 pounds.
My son is 20lbs but they are starting to get a little tight but I don't want to get size 4 and they are too big @arielmarietalks @_akgirl @kevynnsmommy0316
25-32 or something like that. my son is 25 pounds and had to wear size 4 because size 3are to small.
My son is 16lb 6months and wears size 4. I never paid attention to the weight thing, the reason I moved to bigger size was because his thighs legs are chubby and when he was pooping he always exploded in his diaper always went behind on his back and messes up the clothes. No he didn't have diarrhea, nor was he sicks.