How much milk should my baby have?

The number everyone wants

How many ml should she be eating. We asked it repeatedly, in different weeks, with different weights, and each time we wanted a single figure.

The common guide is roughly 150–200ml per kilogram of body weight per day, spread across about eight feeds. So a 3kg baby lands somewhere near 450–600ml a day, which is roughly 55–75ml across eight feeds.

That's a starting point rather than a prescription, and the moment we started treating it as a target we made things harder.

Appetite isn't steady. She'll take 40ml at one feed and 90ml at the next, and both are fine. Averaging across the day is the only version of the number that means anything.

It also assumes a term baby. Ari was born at 33 weeks and the calculation her doctor or nurse used was different from the standard one — smaller stomach, different needs, different targets.

And once she's growing well and feeding effectively, she becomes a better judge of it than the arithmetic. We asked at one point whether 500ml a day was too much, and the answer was that a baby with a good appetite who isn't fussing or vomiting is generally getting it about right.

What we watched instead

Wet nappies. Roughly five or more heavy ones a day was the daily signal that things were fine, and it costs nothing to notice.

Weight, over weeks rather than days. Scales vary, nappies weigh something, and a single reading tells you very little.

And her behaviour. Settled at least some of the time after feeds, alert when awake, and interested in the next one.

Letting her stop

This was the hardest part. When you've measured out what she's supposed to have and she turns away with 20ml left, everything in you wants to get it in.

We learned not to force it. That last bit is where the discomfort comes from, and it teaches her to fight the bottle rather than to trust it.

If she's consistently leaving a lot, that's worth mentioning rather than pushing through — but one feed she didn't finish is just one feed she didn't finish.