A 4-day-old baby typically eats 1 to 2 ounces per feeding if formula-fed, or nurses 8 to 12 times in 24 hours if breastfed. At this age, feedings are frequent and small because your baby’s stomach is roughly the size of a walnut. That’s completely normal, and it means you’ll be feeding around the clock, including overnight.
Formula-Fed Babies at Day 4
The CDC recommends offering 1 to 2 ounces of formula every 2 to 3 hours in the first days of life. Some babies will drain the full 2 ounces, while others consistently take closer to 1. Both are fine. Over a 24-hour period, this works out to roughly 8 to 12 feedings, totaling somewhere around 12 to 20 ounces a day, though the exact amount varies from baby to baby.
If your baby finishes a bottle and still seems hungry (rooting, sucking on fists, fussing), it’s okay to offer a little more. You don’t need to force a schedule. On the other hand, if your baby regularly leaves half an ounce in the bottle, don’t push them to finish. Babies are surprisingly good at regulating their own intake when you follow their lead.
Breastfed Babies at Day 4
Breastfed newborns should nurse about 8 to 12 times every 24 hours, which means a feeding roughly every 1 to 3 hours. You can’t measure ounces at the breast the way you can with a bottle, so frequency and output become your main tracking tools instead.
Day 4 is a significant moment for breastfeeding. Your body is shifting from producing colostrum, the thick, concentrated first milk, to transitional milk. This transition typically happens between days 2 and 5, and you’ll notice your breasts becoming noticeably larger and firmer. Transitional milk comes in much greater volume than colostrum, so your baby will start getting bigger feeds at each session. Many parents describe this as their milk “coming in.” Some babies respond by feeding a bit less frantically, while others cluster-feed even more intensely for a day or two as your supply adjusts.
How to Tell Your Baby Is Getting Enough
Since you can’t weigh every feed at home, diaper output is the most reliable day-to-day indicator. By day 4, you should see 4 to 6 wet diapers and at least 3 dirty diapers in a 24-hour period. The stools at this stage should be yellow and seedy with a soft or liquid consistency. If you’re still seeing dark, tarry meconium stools on day 4, that can signal your baby isn’t taking in enough milk to move things along.
Weight is the other key measure. Newborns lose weight in the first few days after birth, which is expected. A loss of up to about 7% of birth weight is typical. If weight loss reaches 10% or more, that’s a red flag that feeding needs closer evaluation. Your pediatrician will check weight at the first office visit, which usually falls within the first week.
Hunger and Fullness Cues
Rather than watching the clock, watch your baby. Hunger cues are your best guide to when it’s time to feed. Early hunger signs include fists moving toward the mouth, head turning side to side (rooting), lip smacking, sucking on hands, and becoming more alert and active. Crying is actually a late hunger cue. Feeding goes more smoothly when you catch the earlier signals.
Fullness looks different. A satisfied baby will release the breast or pull away from the bottle on their own, turn away from the nipple, and visibly relax their body. You may notice their fists unclenching and their arms going loose. These are signs the feeding is done, even if it lasted only 10 minutes or the bottle isn’t empty.
Signs of Dehydration
Fewer wet diapers than expected is the earliest warning sign that your baby isn’t getting enough to eat. Other signs of dehydration in a newborn include a sunken soft spot (the fontanelle) on top of the head, sunken eyes, few or no tears when crying, and unusual drowsiness or irritability. A baby who is difficult to wake or seems excessively sleepy, even by newborn standards, needs immediate medical attention. At 4 days old, babies should be waking on their own to feed. If yours is sleeping through feedings and you’re struggling to rouse them, that warrants a call to your pediatrician right away.
Night Feedings Are Essential
At 4 days old, your baby’s stomach empties quickly and their calorie needs relative to body size are enormous. There is no stretching out overnight feeds at this age. Most newborns need to eat every 2 to 3 hours around the clock, and many pediatricians recommend waking a baby who sleeps longer than 3 to 4 hours at a stretch until they’ve regained their birth weight. This is true for both breastfed and formula-fed babies. Night feedings also help establish and protect your milk supply if you’re breastfeeding, since the hormone that drives milk production peaks during nighttime hours.
Cluster Feeding Is Normal
Don’t be alarmed if your 4-day-old wants to eat constantly for several hours, then sleeps for a longer stretch. This pattern, called cluster feeding, is extremely common in the first week. It doesn’t mean your milk supply is low or that your baby isn’t getting enough. Cluster feeding actually helps signal your body to produce more milk during the transition from colostrum. It’s exhausting, but it’s temporary and serves a purpose. If your baby seems satisfied after cluster-feeding sessions, has good diaper output, and is gaining weight, everything is working as it should.