How much formula milk does my baby need?

It can be tricky to figure out the right amount of formula for newborns and older babies. And there's no single answer. The amount of formula depends on your baby's age, weight, and whether you're feeding them only formula, or giving formula alongside breastmilk or solids. Your baby’s appetite will also vary from day to day and month to month.

There are some guidelines you can follow. We have a few pointers, too, to help you work out how much to feed your baby and when.

How much formula should I measure out?

Every baby is different, and your best guide is to follow your little one’s cues, but this rough guide can help you estimate how much formula they are likely to need over the course of the first year.

Your baby will take in about 75ml (2 ½ ounces) of formula, per pound of body weight, per day (AAP 2023). Bear in mind that they may want less than this in the first week, before they settle down to a pattern of feeding (HC 2023).

So, if your baby weighs 3kg (6.6lbs), they will need between 450ml (15oz) and 600ml (20oz) of formula over a 24-hour period to feel full.

These portions are only a rule of thumb. Just as your appetite varies with each meal, your baby isn't going to want the same amount of formula at each feed. There’s no need to push your baby to finish a bottle, even if there is only a little bit left.

Do not chill and reuse what baby leaves behind in their bottle. Just throw it out. And be sure to get rid of formula that has been out of the fridge for two hours or more as well. (The combination of infant formula and your baby’s saliva can cause bacteria to grow that can make them sick.)

How will feeding change as my baby grows?

How much formula your baby needs depends not only on their weight and age. Here’s a rough month-by-month guide to help you work out how much to give your baby:

• How much should a newborn drink? During the first week, try giving your baby between 30ml and 60ml (1oz to 2oz) at each feed. Their tummy is so small at first that they won’t be able to manage much more than this in one go, and will need to be fed often.
• By the time your baby is between three and eight weeks, they will want between 90ml and 150ml (3oz and 5oz) at each feed. They will consume 420ml to 7800ml (17oz and 35oz) in one day. You'll soon sense if your baby needs more, as they will finish their bottle quickly and may even look around for second helpings!
• When your baby is between two and five months, they may want between 120ml and 180ml (4oz and 6oz) at a time. At this stage, they will have between 600ml to over a litre a day (20oz and 39oz).
• When you start giving your baby solids, at about six months of age, their daily intake of formula is likely to slowly decrease to about 720ml (24oz).
• When your baby is between nine and 12 months, you can start to replace formula with pasteurized 3.25% (homogenized) milk, as long as they are eating iron-rich foods at most meals. As your baby eats more solid foods they will need to drink less formula and milk.
• By their first birthday, your baby will need about 500ml (16oz) of milk each day, along with a varied diet (AHS 2019). (Infant formula isn’t needed for most healthy babies after 12 months, unless advised by your doctor.) If your baby doesn’t want this amount of milk, you can always try them with full-fat milky foods such as yogurt and cottage cheese.

Bear in mind that these are only rough guidelines. Your baby will let you know if they are getting too much or too little formula. If you’re at all unsure, talk to their doctor.

When should I replace formula with solids?

When you start your baby on solids at about six months old, they won’t be eating a wide enough range of foods to get all the goodness they need. Carry on giving your baby formula until they are a year old, as well as drinks of water. There’s no need to give babies water to drink until they are six months old. After that, small amounts can be offered as a drink, along with breastmilk or formula (AHS 2013).

Since vitamin D is added to infant formula, most full-term babies who are getting formula don’t need a supplement. You can start giving your baby vitamin D drops from six months, as they begin to be weaned off formula (CPS 2021).