A 3-day-old baby typically takes in about 15 to 30 ml (roughly half an ounce to one ounce) per feeding, eating 8 to 12 times every 24 hours. That sounds tiny, but it matches a newborn’s stomach, which at 3 days old holds only about 22 to 27 ml, roughly the size of a walnut. Feeding little and often is exactly how newborns are designed to eat.
Stomach Size Sets the Pace
At birth, a baby’s stomach holds just 5 to 7 ml, about the size of a hazelnut. By day 3 to 5, it stretches to around 22 to 27 ml. That’s why newborns need to eat so frequently: their stomachs empty quickly, and they can only take in small amounts at a time. Parents sometimes worry their baby isn’t getting enough because each feeding seems so brief, but those frequent, small meals add up over the course of a day.
Breastfed Babies at 3 Days
A breastfed 3-day-old should nurse about 8 to 12 times in 24 hours, which works out to roughly every 2 to 3 hours. Each session may last anywhere from 10 to 20 minutes per breast, though some babies are faster and some take longer. There’s no exact milliliter target for breastfeeding because you can’t measure what the baby takes directly, so you rely on feeding frequency and diaper output instead.
Day 3 is also when your body starts shifting from colostrum to transitional milk. Colostrum is the thick, concentrated first milk your breasts produce in the hours after birth. Starting around day 2 to 5, transitional milk gradually replaces it. You may notice your breasts feeling fuller and warmer, and the milk changing from a golden color to a thinner, bluish-white. This transition means your baby starts getting more volume per feeding, which is why many parents notice their newborn seeming more satisfied around this time. Transitional milk continues for about two weeks before fully mature milk takes over.
Formula-Fed Babies at 3 Days
If your baby is drinking formula exclusively, the CDC recommends starting with 1 to 2 ounces (30 to 60 ml) every 2 to 3 hours in the first days of life. A 3-day-old’s stomach can’t comfortably hold much more than an ounce at a time, so don’t worry if your baby only takes the lower end of that range. Offer small amounts and let your baby tell you when they’ve had enough. It’s better to feed more often than to push larger volumes at once.
How to Tell Your Baby Is Hungry
Crying is actually a late hunger signal. Well before that point, a hungry newborn will put their hands to their mouth, turn their head toward your breast or the bottle (called rooting), pucker or smack their lips, or clench their fists. Catching these early cues makes feeding easier because a calm baby latches and swallows more effectively than one who’s already upset.
When your baby is full, you’ll notice the opposite: their mouth closes, they turn their head away from the breast or bottle, and their hands relax and open. Letting your baby stop when they show these signs helps them regulate their own intake from the very beginning.
Tracking Diapers as a Feeding Check
Since you can’t measure breastmilk intake directly, diaper counts are the most reliable way to confirm your baby is eating enough. On days 3 and 4, expect at least 3 to 4 wet diapers and at least 3 poopy diapers in a 24-hour period. The stools often shift from the dark, sticky meconium of the first two days to a greenish-brown transitional stool and eventually to the yellow, seedy stools typical of breastfed babies. For formula-fed babies, stools tend to be firmer and tan or yellow.
If your baby is consistently hitting those diaper numbers, they’re almost certainly getting enough milk, even if individual feedings seem short.
Weight Loss in the First Few Days
Nearly all newborns lose weight after birth. This is normal. Most lose somewhere between 5% and 7% of their birth weight in the first few days, and they typically regain it by 10 to 14 days old. A weight loss of 10% or more needs careful assessment, as it can signal feeding difficulties or inadequate milk transfer. Your pediatrician or midwife will track your baby’s weight at early checkups specifically for this reason.
Signs Your Baby Isn’t Getting Enough
A few red flags suggest a 3-day-old may be underfed or becoming dehydrated:
- Fewer wet diapers than expected: fewer than 3 wet diapers by day 3 warrants attention.
- Unusual sleepiness: a baby who is difficult to wake for feedings or seems limp and drowsy beyond normal newborn sleepiness.
- Few or no tears when crying and dry lips or mouth.
- A sunken soft spot on the top of the head (the fontanelle dips inward instead of lying flat).
- Dark yellow urine: newborn urine should be pale. Concentrated, dark urine suggests the baby needs more fluid.
Any of these signs, especially in combination, call for a prompt evaluation. Dehydration in newborns can escalate quickly because of their small body size and limited reserves.