A 5-week-old typically eats 3 to 4 ounces per feeding if formula-fed, or nurses 8 to 12 times in 24 hours if breastfed. That works out to roughly 24 ounces of formula or breast milk total per day, though every baby varies. The most reliable guide isn’t a number on a chart; it’s your baby’s own hunger and fullness cues.
Formula Feeding at 5 Weeks
At 5 weeks, most formula-fed babies take between 3 and 4 ounces per bottle, feeding every 3 to 4 hours. Some feedings will be bigger, some smaller. A baby who drains 4 ounces at one feeding might only take 2.5 at the next, and that’s completely normal. Over a full day, most 5-week-olds consume somewhere between 20 and 28 ounces of formula total.
A newborn’s stomach at this age holds about 4 to 6 ounces at maximum capacity, which is why small, frequent feedings work better than trying to stretch intervals and offer larger bottles. If your baby consistently finishes every bottle and still seems hungry, it’s fine to add an extra half ounce or ounce. But routinely offering much more than 4 ounces at this age can override your baby’s natural ability to stop when full.
Breastfeeding at 5 Weeks
Breastfed babies eat more frequently than formula-fed babies because breast milk digests faster. Expect your baby to nurse 8 to 12 times in 24 hours, which can mean a feeding roughly every 2 to 3 hours. Some sessions will last 30 minutes, others barely 10. Both are normal.
The tricky part with breastfeeding is that you can’t measure ounces. Instead of tracking volume, you’re watching for signs that your baby is getting enough (more on that below). One reassuring thing to know: babies have a strong innate ability to regulate their own intake. A baby who nurses frequently isn’t necessarily getting too little at each session. They may simply prefer smaller, more frequent meals.
How to Tell Your Baby Is Getting Enough
Diaper output is the most straightforward way to confirm adequate intake. By 5 weeks, your baby should produce at least 6 wet diapers per day. The number of dirty diapers varies more widely at this age, but you should still see them regularly.
Steady weight gain is the other key marker. Most pediatricians expect babies to regain their birth weight by 2 weeks and then gain about 5 to 7 ounces per week through the first few months. Your baby’s checkups will track this, but if you’re worried between visits, many pediatric offices will let you come in for a quick weight check.
Reading Hunger and Fullness Cues
Rather than feeding on a rigid schedule, pediatric guidelines emphasize responsive feeding, which means watching your baby and letting them tell you when they’re hungry and when they’ve had enough. Paying attention to these cues helps your baby maintain their natural ability to self-regulate how much they eat. Ignoring them, particularly by pushing a baby to finish a bottle, has been linked to overfeeding.
Hunger cues at this age include:
- Bringing hands to their mouth
- Turning their head toward your breast or the bottle (rooting)
- Smacking, puckering, or licking their lips
- Clenching their fists
Crying is actually a late hunger cue. If you can catch the earlier signals, feeding tends to go more smoothly because your baby isn’t already frustrated.
Fullness cues include:
- Closing their mouth
- Turning their head away from the breast or bottle
- Relaxing their hands, letting their fists open
When you see these signs, stop the feeding even if the bottle isn’t empty. Letting your baby decide when they’re done is one of the most important habits to build early.
The 6-Week Growth Spurt
At 5 weeks, you’re on the doorstep of one of the most noticeable growth spurts. Babies commonly go through a growth spurt around 6 weeks (others happen around 2 to 3 weeks, 3 months, and 6 months). During a spurt, your baby may suddenly want to eat much more often, sometimes as frequently as every 30 minutes, and may seem fussier than usual between feedings.
This can feel alarming, especially for breastfeeding parents who worry their supply has dropped. It hasn’t. Your baby is temporarily increasing demand to signal your body to produce more milk. Growth spurts typically last only a few days, and feeding patterns return to normal afterward. For formula-fed babies, it’s fine to offer an extra ounce per bottle or add a feeding or two during these stretches.
Night Feedings at 5 Weeks
Babies between 0 and 3 months old generally wake and feed at night in the same pattern as during the day. At 5 weeks, that means your baby will likely still need to eat every 2 to 4 hours overnight, sleeping in short stretches of 2 to 3 hours between feeds. This is biologically normal, not a sign of a problem.
Some babies this age will occasionally sleep one longer stretch of 4 to 5 hours, often in the first half of the night. If your baby is healthy, gaining weight well, and producing enough wet diapers, you generally don’t need to wake them to eat. But most 5-week-olds will wake on their own when they’re hungry.
Combination Feeding
If you’re supplementing breast milk with formula, the same overall principles apply. Watch your baby’s cues, aim for at least 8 feedings in 24 hours between breast and bottle combined, and track diaper output to make sure intake is adequate. When offering a bottle of formula after nursing, start with a small amount (1 to 2 ounces) and let your baby decide if they want more. This prevents the bottle from replacing a breastfeeding session entirely, which can gradually reduce your milk supply if that’s not your goal.
Keep in mind that babies under 6 months get everything they need nutritionally from breast milk, formula, or a combination of the two. No water, juice, or other liquids are needed or recommended at this age.