I think every baby will be different and it also very much depends on when they feed now and how much solid food they are eating. We did BLW, so at 8-9 months, my daughter was still mostly eating just for play rather than massive meals. But she would have a bottle when she woke up, one mid morning (10am ish), one early afternoon, one late afternoon and one at bedtime, plus 3 meals a day (so 5 bottles). She also had one bottle overnight until 9 months when she dropped that. By 10/11 months, it was 4 bottles during the day with the late afternoon one being very small and mostly a snack. It would be roughly 180-260 ml each depending, but it's very much trial and error. Formula tastes different (not as nice) than breastmilk, so you may find your LO tastes less than you might expect to start.