A 3-day-old baby’s stomach holds roughly 22 to 27 milliliters at a time, about the size of a walnut or ping-pong ball. That means feedings are small but frequent: 8 to 12 times in a 24-hour period, or roughly every 1 to 3 hours.
Stomach Size at Day 3
Your newborn’s stomach grew rapidly in just 72 hours. At birth it held only about 5 to 7 milliliters (the size of a cherry). By day 3, it has expanded to walnut size, holding around 22 to 27 milliliters per feeding. That’s still less than one ounce. This is why newborns need to eat so often: they can only take in a small amount at a time, and they digest it quickly.
Breastfeeding Amounts and Frequency
If you’re breastfeeding, you won’t be measuring milliliters, and that’s completely normal. The guideline is to nurse on demand, aiming for at least 8 to 12 sessions in 24 hours. Some babies cluster-feed, eating several times within a couple of hours and then sleeping a longer stretch. Others space feedings more evenly. Both patterns are fine as long as the total number of feedings stays in that range.
Day 3 is also when your milk typically begins to change. For the first two days, your breasts produce colostrum, a thick, yellowish fluid that comes in very small volumes but is packed with antibodies and nutrients. Starting around day 2 to 5, transitional milk gradually replaces colostrum. You may notice your breasts feel fuller and warmer, and the milk shifts to a thinner, bluish-white color. This increase in volume lines up perfectly with your baby’s growing stomach capacity.
Each nursing session at this age usually lasts 10 to 20 minutes per breast, though some babies are efficient feeders who finish faster. Let your baby finish one breast before offering the other. Not every baby will want both sides at every feeding.
Formula Feeding Amounts
For formula-fed babies, the CDC recommends starting with 1 to 2 ounces (30 to 60 milliliters) per feeding every 2 to 3 hours. At 3 days old, most babies land closer to the 1-ounce end, since their stomachs can only comfortably hold about an ounce. Over the next week or two, your baby will gradually take more per feeding and may go slightly longer between bottles.
It’s better to prepare smaller bottles and offer more if your baby still seems hungry than to push a larger bottle and risk overfeeding. Newborns don’t have great portion control, and a baby who gulps down too much formula at once is more likely to spit up or feel uncomfortable.
How to Tell Your Baby Is Hungry
Crying is actually a late hunger signal. By the time a 3-day-old is wailing, they’ve already been giving subtler cues for a while. Early signs to watch for include putting hands to their mouth, turning their head toward your breast or the bottle (called rooting), puckering or smacking their lips, and clenching their fists. Feeding at the first sign of these cues makes latching easier and keeps the baby calmer during the feeding.
When your baby is full, the signals flip. They’ll close their mouth, turn their head away from the breast or bottle, and visibly relax their hands. These are reliable signs that the feeding is done, even if the bottle isn’t empty or the nursing session was shorter than usual.
Tracking Output: Wet and Dirty Diapers
Since you can’t measure how many milliliters a breastfed baby swallowed, diapers become your best tracking tool. On day 3, you should see at least 3 wet diapers and 2 to 3 dirty diapers in a 24-hour period. A handy rule of thumb for the first week: the minimum number of wet diapers roughly matches the baby’s age in days (1 on day 1, 2 on day 2, 3 on day 3, and so on, until it levels off at 6 or more per day by the end of the first week).
The stools themselves change during this period. By day 3, they’re typically shifting from the dark, tarry meconium of the first day or two toward a greenish-brown transitional stool. Within a few more days, breastfed babies produce loose, yellow, seedy stools, while formula-fed babies tend toward firmer, tan-colored stools.
Signs Your Baby Isn’t Getting Enough
Most newborns eat well with a little patience and practice, but it’s important to recognize the signs of inadequate intake early. Fewer wet diapers than expected for the day of life is the most practical red flag. Other signs of dehydration in a newborn include a sunken soft spot on top of the head, sunken eyes, few or no tears when crying, and unusual drowsiness or irritability. A baby who is consistently difficult to wake for feedings or who seems too sleepy to eat may not be getting enough.
Weight is also tracked closely in these early days. Most newborns lose 5 to 7 percent of their birth weight in the first few days, and that’s expected. Losses beyond 10 percent, or a baby who hasn’t started regaining weight by day 4 or 5, signal that feeding needs to be evaluated.
Practical Tips for Day 3
Skin-to-skin contact helps stimulate feeding instincts and supports milk production. Holding your baby against your bare chest, especially right before a feeding, can make latching easier and encourage your baby to eat more effectively. Rooming in with your baby (keeping them in the same room rather than a separate nursery) makes it much easier to catch those early hunger cues and feed on demand.
If you’re breastfeeding, avoid introducing bottles or pacifiers in these first few days unless medically necessary. Establishing a strong breastfeeding routine first helps your milk supply adjust to your baby’s needs. Your body calibrates production based on how often and how thoroughly your baby empties the breast, so skipping or supplementing feedings during this window can interfere with that process.
For formula-feeding parents, pace the feeding by holding the bottle at a slight angle and letting your baby take breaks. This mimics the natural rhythm of breastfeeding and gives your baby time to register fullness before overdoing it.