A 4-day-old baby typically drinks 1 to 2 ounces (30 to 60 mL) per feeding, eating 8 to 12 times over a 24-hour period. That works out to roughly 8 to 24 ounces total per day, though most babies at this age land somewhere in the middle of that range. The exact amount varies depending on whether your baby is breastfed or formula-fed, and on your baby’s size and appetite.
How Much Per Feeding
At four days old, your baby’s stomach is still tiny, roughly the size of a walnut. Breastfed babies take in about 1 ounce per feeding at 72 hours old and gradually work up to 1 to 2 ounces per feeding by the end of the first week. Formula-fed newborns follow a similar pattern, averaging 1 to 2 ounces per session during the first week.
These amounts sound small, but they match what your baby’s body can actually handle. Trying to push more milk into a feeding than your baby wants can cause spit-up and discomfort. Smaller, more frequent meals are the norm right now.
Breastfeeding vs. Formula Feeding
Breastfed babies tend to eat more frequently than formula-fed babies because breast milk digests faster. If you’re breastfeeding, expect to feed every 2 to 3 hours, which adds up to about 8 to 12 feedings in 24 hours. Formula-fed newborns typically eat 6 to 10 times per day because formula takes a bit longer to digest.
If you’re breastfeeding, you won’t be able to measure exactly how much your baby takes in at each session, and that’s completely normal. At day 4, your body is transitioning from colostrum (the thick, concentrated first milk) to transitional milk. You may notice your breasts feeling fuller and warmer, and the milk shifting from a yellowish color to a bluish-white. This changeover happens between days 2 and 5, and it means the volume of milk available to your baby is increasing right when they need it to.
How to Tell If Your Baby Is Getting Enough
Since you can’t pour breast milk into a measuring cup mid-feed, the most reliable signs that your baby is eating enough are output and weight. By day 4, your baby should be producing at least 3 to 4 wet diapers a day, with that number climbing over the next few days. Stool frequency varies, but you should see some bowel movements daily.
Most newborns lose weight in the first few days after birth. This is expected. Babies typically start regaining weight between days 3 and 5, which means day 4 is right around the turning point. A weight loss of up to about 7% of birth weight is common, but a loss of 10% or more needs careful evaluation. If your baby was 7 pounds 8 ounces at birth, for example, losing more than about 12 ounces would be a flag worth discussing with your pediatrician.
Reading Your Baby’s Hunger Cues
Rather than watching the clock, the best approach at this age is to feed on demand, responding to your baby’s signals. Early hunger cues include putting hands to their mouth, turning their head toward your breast or bottle (called rooting), lip smacking or licking, and clenching their fists. Crying is actually a late sign of hunger. A very upset baby can have a harder time latching, so catching the earlier signals makes feeding smoother for both of you.
Fullness cues are just as important. When your baby is satisfied, they’ll close their mouth, turn their head away from the breast or bottle, and relax their hands. These are reliable signals that the feeding is done. You don’t need to coax a baby to finish a bottle if they’re showing clear signs of being full.
What Changes Over the Next Few Days
Feeding volumes increase quickly during the first two weeks. By one week, most babies are consistently taking 1 to 2 ounces per feeding. By two weeks, that often climbs to 2 to 3 ounces. Your baby’s appetite will guide this increase naturally, so there’s no need to follow a rigid schedule. As long as your baby is regaining their birth weight (most reach it again by 10 to 14 days old), producing enough wet and dirty diapers, and seeming satisfied after feedings, you can trust that the amount they’re taking is right for them.
If your baby seems constantly hungry, isn’t producing enough wet diapers, or hasn’t started regaining weight by day 5, those are signs to check in with your pediatrician or a lactation consultant. Small adjustments to latch, positioning, or feeding frequency can often make a big difference in those early days.