every baby different. hard to tell you when. my girl now 8mths still waking up 1-2 times a night. she was waking up every 2.5-3hrs when she was newborn till 1.5mths old. then slowly increase to 3-4 hours till about 4.5mths old then she start to sleep 4-6hrs stretch. then at about 5.5mths 10hrs at most but usually also around 6-8hrs stretch. till now still this schedule...btw, she is purely on breastmilk.