..rule of thumb!
So there's a rule of thumb you can kind of go by... you take how many pounds your baby weighs.. multiple that by 2.5 and wa la! typically, that's how many ounces throughout a day your baby should be eating!
Obviously some babies will be different than this - as always consult your pediatrician if you have ANY questions about how many ounces!
My other rule of thumb is.. when the baby is hungry FEED THEM - I believe in on demand feeding, not scheduled!