After the first few daysYour formula-fed newborn will take from 60–90ml of formula per feeding and will eat every three to four hours on average during their first few weeks. (Breastfed infants usually take smaller, more frequent feedings than formula-fed infants).
During the first few weeksIf your baby sleeps longer than four to five hours and starts missing feedings, wake them up and offer a bottle.
By the end of the first monthYour baby will be up to at least 120ml per feeding, with a fairly predictable schedule of feedings about every four hours.
By six monthsYour baby will consume 180–240ml at each of four or five feedings in twenty-four hours.
Instead of going by fixed amounts, let them tell you when they’ve had enough. If they become fidgety or easily distracted during a feeding, they are probably finished. If they drain the bottle and continues smacking their lips, they might still be hungry. There are high and low limits, however. Most babies are satisfied with 90–120ml per feeding during the first month and increase that amount by 30ml per month until they reach a maximum of about 210–240ml. If your baby consistently seems to want more or less than this, discuss it with your pediatrician. Your baby should drink no more than 960ml of formula in twenty-four hours. Some babies have higher needs for sucking and may just want to suck on a pacifier after feeding.
Initially it is best to feed your formula-fed newborn on demand, or whenever they cry because they are hungry. As time passes, they’ll begin to develop a fairly regular timetable of their own. As you become familiar with their signals and needs, you will be able to schedule their feedings around their routine.
Between two and four months of age (or when the baby weighs more than 5.4 kg), most formula-fed babies no longer need a feeding in the middle of the night, because they’re consuming more during the day and their sleeping patterns have become more regular (although this varies considerably from baby to baby). Their stomach capacity has increased which means they may go longer between daytime feedings. If your baby still seems to feed very frequently or consume larger amounts, try distracting them with play. Sometimes patterns of obesity begin during infancy, so it is important not to overfeed your baby.
The most important thing to remember, whether you breastfeed or bottlefeed, is that your baby’s feeding needs are unique. No book―or website―can tell you precisely how much or how often they need to be fed or exactly how you should handle them during feedings. You will discover these things for yourself as you and your baby get to know each other.
Caring for Your Baby and Young Child: Birth to Age 5, 6th Edition (Copyright © 2015 American Academy of Pediatrics)