How much milk does a baby need? A plain guide in ml and oz

Oct 2

3 min read

Baby bottle of milk on a kitchen counter beside a muslin

The bottle is marked in oz. The tin is in ml. Someone at the clinic said a number you can no longer remember, and it is now 2:14am and you are doing conversions in your head while holding a baby with one arm.

Here is the plain version, with the official guidance clearly marked as official, and the rest clearly marked as us.

What the NHS says about how much your baby needs

This is the part that should come from the NHS rather than from an app, so here it is in their terms, with a link so you can read it yourself.

On its Formula milk: common questions page, the NHS deliberately does not give a single amount. It says newborns need quite small amounts to start with, that the amount varies from baby to baby, and that babies vary in how often they want to feed and how much they want to drink. Its advice is to feed your baby when they show signs that they want it, and that babies tend to feed little and often so may not finish a bottle.

For knowing whether your baby is getting enough, the NHS points at wet and dirty nappies and weight gain, which your health visitor will check, rather than volumes, and says to expect around six wet nappies a day from a few days after birth.

Whether your baby is breastfed or bottle fed, the NHS encourages responsive feeding: following your baby's own cues for when they are hungry and when they have had enough. If you are bottle feeding, the NHS says the formula packet gives a guide, and your health visitor can help if you are unsure.

For your baby specifically, ask your health visitor or GP. They know the weight, the history and the context. We don't, and neither does any app.

Why intake moves around so much

Whatever the guide says, real days vary. Things that change how much a baby takes:

Growth spurts. A few days of taking noticeably more, then back to normal.
Time of day. Many babies feed more often in the evenings, and that is a very common experience.
Being under the weather. Many parents notice feeds dip a little when their baby is unwell.
Teeth, heat, a busy day out. All of it moves the numbers, and none of it means something is wrong.

Why intake changes day to day: growth spurts, little and often versus bigger feeds, every baby has their own normal range. Worried about weight? Speak to your health visitor

Ml and oz, so you can stop converting

One fluid ounce is roughly 30ml. So a 4oz bottle is about 120ml, and a 6oz bottle is about 180ml.

That is the whole conversion, and you should not have to do it at all. Log in whichever unit the bottle in your hand is marked in and let the app hold both.

If you are breastfeeding, the question changes

There is no number on the side of a breast, which is either liberating or maddening depending on the day. Instead of volume, the useful things to notice are how often your baby feeds, how long feeds last, nappies, and how your baby seems in themselves. That is the same set of signs the NHS points at for formula.

Logging which side, and for how long, also solves the 2:14am question that has no good answer: which one was it last time.

One day tells you almost nothing

A day where your baby takes much less than usual is common and usually unremarkable. A week where intake is steadily dropping is different information.

You cannot tell those apart from a single day, and you certainly cannot tell them apart from memory at the end of a long one. Written down, across a week, the difference is obvious.

When to speak to someone

Please contact your health visitor or GP if:

you are worried about weight gain, or your baby seems more sleepy than usual, or unwell
wet nappies have dropped off noticeably
intake has dropped for several days rather than one
feeding has become painful, or you are finding it hard going in any way

The NHS says to call 999 or go to A&E if your baby is difficult to wake or cannot be woken, or has not had a wee in the past 12 hours.

Turning up with a fortnight of real logs makes that conversation far more useful than trying to remember Tuesday.

Littles is free to download, and logging feeds, sleep and nappies stays free for as long as you want it. Breast, bottle and pumping, in ml or oz.

The feeding and sleep analysis screens are part of premium. Two weeks free to try, then £6.99 a month or £50 a year.

Sources: NHS guidance on formula milk and bottle feeding; NHS guidance on breastfeeding and signs your baby is getting enough milk; NHS guidance on when to call 999 or go to A&E.