I was always worried about this early on (and still am). From what I could tell it had more to do with weight. Multiply their weight by 2.5; that would be the total daily oz they shoul have. Then divide that as you wish amongst however many feedings they take per day.
This is a guideline though and you're better off letting your LO guide you. They'll generally stop when they're full. If they're polishing off a bottle rather quickly and still seem hungry, offer more.
Here's a chart that might help give you a general idea.