Ftm mum help?

How do we know how much is enough milk formula to give a baby? Dr recommend to topup 5mls every hr but depends on baby. Newborn is now 4weeks, im at 100ml is it enough for a 4 weeks or how de we know how many mls to give a milk formula and ideally for a 4weeks old how much milk formula do u all give? and usually whats the max to not go to overfeeding? do help me out. #1stimemom #advicepls