AAP recommends roughly 2.5 oz of formula per pound of body weight per day, capped at about 32 oz daily. This is a population-level guideline — individual babies vary 20% in either direction and that's normal.
Watch the baby, not the bottle. Hunger cues (rooting, hand-to-mouth, fussiness) and fullness cues (turning away, slowing down, falling asleep) matter more than exact ounces. If your baby consistently finishes every bottle and seems hungry, increase. If they leave a lot, you can reduce.
Source: HealthyChildren.org (AAP) — "Amount and Schedule of Formula Feedings."