My little one is 6 weeks old and has 6 oz. every three hours (48 oz. a day)! The doc said it was fine if that's what he wanted. Porkchop seems to be moving up to 7 oz., soon, too, so goes to show that, as Lolly suggested, they self-regulate. If he screams and drains his every bottle, he's wanting more. If he leaves 1/2 an ounce or so in the bottle, he's good.