How many oz of milk should the 2 months old baby need to drink?

Enough: This varies with size & activity. The average infant takes about half their poundage as ounces/feed , like a 10 pounder takes 5 and so on. As long as they take well enough to grow they seem to sort it out.

Start with 3 oz every 3 hours, then if baby can manage, 4 oz every 4 hours while parents are awake. The baby will make it known if s/he needs more.