That depends on how often you plan to wash your bottles. You could get by with a minimum of two bottles: one for feeding and one that’s drying while you feed. But you’d have to wash the bottle and nipple right after each use.; Some parents prefer to have 10 to 12 bottles so they have enough to use all day and then wash them all at once in the evening.; It also depends on whether you plan to hand-wash the bottles or place them in the dishwasher. Most people don’t run their dishwashers more than once a day. If that’s the case, you’ll need enough bottles to feed your baby all day. The older your baby gets, the fewer bottles your baby will need as they start eating solid foods.