Baby feeding chart, by age.

Formula amounts are the American Academy of Pediatrics’ (AAP); the timings are the AAP’s and the CDC’s; breastfeeding is the CDC’s, the NHS’s and the World Health Organization’s. A rule of thumb from the AAP: about 2½ ounces of formula a day for every pound your baby weighs (75 ml for every 453 g, roughly 165 ml per kilo), and no more than about 32 ounces (960 ml) in 24 hours.

Sources differ a little on the very first days: the CDC suggests starting at 1 to 2 ounces, while the AAP says babies might take only half an ounce a feed for the first day or two.

You can’t measure exactly how much milk a breastfed baby takes, the AAP says, so you go by your baby instead. In the first few days, babies feed every 1 to 3 hours, and at least 8 to 12 times every 24 hours in the first few weeks (NHS). The World Health Organization puts it at 8 to 12 times a day through the first six months.

Over the first weeks and months, most exclusively breastfed babies settle into feeding every 2 to 4 hours, with some clusters of feeds close together and, often, one longer stretch of 4 to 5 hours (CDC). Feed when you see signs of hunger: that’s feeding on demand.

Two reassurances from the NHS: it isn’t possible to overfeed a breastfed baby, and night feeds help, because that’s when your body makes more of the hormone prolactin.

A newborn’s belly is tiny, so start small (CDC): 1 to 2 ounces every 2 to 3 hours in the first days, 8 to 12 feeds in 24 hours. Amounts grow quickly after that, as in the chart.

Let your baby set the pace. If they get fidgety or easily distracted during a feed, they’re probably finished (AAP).

Night feeds drop away for many formula-fed babies between 2 and 4 months, or once they weigh more than 12 lb (5.4 kg), when most no longer need a feed in the middle of the night (AAP).

The CDC’s signs of hunger, from birth to 5 months:

• Hands to the mouth
• Turning their head toward the breast or bottle
• Puckering, smacking or licking their lips
• Clenched hands

Crying is often a late sign of hunger, so try to feed before it starts.

And the signs they’re full: they close their mouth, turn their head away from the breast or bottle, and relax their hands.

• Wet nappies. Only 2 or 3 a day in the first couple of days, then at least 5 to 6 a day after the first 4 to 5 days (AAP). The NHS looks for at least 6 heavy, wet nappies every 24 hours from day 5.
• Weight. Babies lose a little weight after birth, but no more than 8 to 10% in the first few days (AAP). By two weeks they should be back to their birth weight and gaining (AAP).
• Poos. The counts vary by source and by feeding: the AAP looks for at least 4 a day by day four in a breastfed baby, the NHS for at least 2 soft, yellow poos from day four, and at least 1 a day for a formula-fed baby.

At around 6 months (WHO, NHS, AAP), and not before 4 months (CDC). The NHS lists three signs your baby is ready: they can stay sitting up and hold their head steady, coordinate their eyes, hands and mouth to pick up food and put it in, and swallow food rather than push it back out.

Milk stays the main drink: breast milk or formula through the first year (NHS). And a few don’ts from the AAP: no baby cereal in a bottle, because your baby could choke, and no juice before 12 months.

Water: the WHO says not to give water to a baby under six months, even on hot days, and a fully breastfed baby doesn’t need any until they start solids (NHS). For formula-fed babies under 6 months, the NHS says small sips of cooled boiled water may help in hot weather. Ask your doctor or health visitor if you’re unsure.

• Fewer than six wet nappies a day after the first week (AAP), or a sunken soft spot on the head (NHS).
• Your baby still seems hungry after most feeds: have them weighed (AAP).
• Still under birth weight at two weeks (AAP).

Get urgent help (NHS) if your baby isn’t feeding, keeps vomiting for 24 hours, has red, black or brown vomit, or hasn’t had a wet nappy for 12 hours.