dad feeding newborn baby formula bottle
profile picture of Natalie Gingerich Mackenzie
Natalie Gingerich Mackenzie
Contributing Writer

How Much Should a Newborn Eat?

Is baby getting enough milk? Learn how often and how much a newborn should be eating.

If you find yourself fretting over your newborn feeding schedule, you’re not alone. Questions like “how much should a newborn eat?” and “how often should I feed baby?” are some of the most common concerns among new parents. After all, baby is growing by leaps and bounds. She’ll grow more in the first year than at any other point in her life, doubling in size by the time she’s 5 months old and tripling by the end of her first year—so it’s important to feed baby the fuel she needs to power through each stage of development. Whether you opt for breast milk or formula, here’s what you need to know to make sure baby is eating enough.

How Much Breast Milk Should A Newborn Eat?

Wondering how much should a newborn eat? “As pediatricians, we say to feed on demand,” says Jennifer Trachtenberg, MD, a pediatrician in New York City and an assistant clinical professor of pediatrics at The Mount Sinai School of Medicine. And luckily, when all goes right, breastfeeding is an ingenious, self-sufficient system. When baby suckles, it stimulates your breasts to produce just the right amount of milk to meet his nutritional needs. When baby needs more (because of a growth spurt, for example) he suckles more, causing your body to crank up production. Genius. Of course, that’s presuming that baby—and your breasts— cooperate.

It’s hard to clock how much a newborn eats when you’re breastfeeding. Use these guidelines to make sure baby is eating enough.

How many ounces should a newborn eat at a time? From the time your milk comes in a few days after birth, baby will likely take in two to three ounces at each feeding, working his way up to four ounces by the end of the first month. To gauge roughly how much milk baby needs, try this quick, easy calculation: Multiply baby’s weight by two and a half. For example, an eight-pound baby should be eating about 20 ounces a day.

In terms of how often you should feed baby, you can expect a newborn to breastfeed as much as every two to three hours (or more!), or 8 to 12 times a day. While baby (and mom) are still figuring out how to breastfeed, it can take 20 to 45 minutes per feeding, or more. But all that suckling helps to establish your milk supply, so it’s time well spent. As baby’s stomach gets bigger and can hold more milk at a time, she’ll be able to go longer between feedings—about three to four hours. She’ll also get more efficient, usually taking in 90 percent of the milk she needs within the first 10 minutes of nursing.

How Much Formula Should A Newborn Eat?

One advantage to formula-feeding is parents can measure every ounce of milk baby guzzles down. But it can pose its own challenges too: While babies are blissfully free from concepts like the clean plate (or empty bottle) club, parents aren’t. Here’s a breakdown of how much formula a newborn should eat.

Ounce for ounce, formula has the same average calories as breast milk, so the total amount that breastfed and formula-fed babies will need to eat in a day is basically the same: about two and a half times baby’s weight in pounds. The newborn feeding schedule for formula, however, might be a little different. Since babies tend to digest formula more slowly, they’ll go longer between feedings. Baby will likely get hungry every three to four hours, eating about two ounces per feeding as a newborn and progressing to four ounces by the end of the first month. Expect to add about an ounce per month until baby is eating six to eight ounces of formula at a time, which usually happens when baby is 6 months of age. In general, 32 ounces of formula a day is the most baby will ever need. (When she’s hungry for more than that, it may mean she’s ready to start eating solids, which typically happens around the six-month mark.)

What If You’re Breastfeeding And Formula-Feeding?

For moms who do a blend of breast milk and formula, there are no set rules for how often and how much a newborn should eat of each. You’ll want to aim for at least six to eight feedings per day of one type of milk or the other (fewer as baby gets older)—but since breast milk and formula are nutritionally equivalent, it’s simply a matter of finding the mix that works best for you and baby. However, the American Academy of Pediatrics recommends exclusive breastfeeding for the first six months. Even if you plan to eventually supplement with formula, breastfeeding during that critical period can help better establish your breast milk supply for the months ahead.

Age-By-Age Feeding Guide

Still wondering how much should a newborn eat, and how often? The following feeding chart, based on information from the Children’s Hospital of The King’s Daughters, breaks down feeding amounts and frequency by age, so you don’t have to constantly worry if you have a hungry baby on your hands. Around 6 months old, you can start introducing solid foods into baby’s diet (which is a whole new exciting adventure).

Signs Baby Is Eating Enough

When it comes to newborns, how often you should feed baby depends on how much milk your newborn wants. Keep an eye out for signs you have a hungry baby—like if she wakes up and starts rooting, or suckling or moving her mouth—preferably before she starts fussing or crying. Pay attention to baby’s cues even while you feed. You’ll know she’s still hungry if she’s actively suckling and audibly swallowing. When she stops suckling, relaxes her hands and has that sleepy, relaxed “milk-drunk” look, you’ll know baby has eaten enough.

Checking baby’s diaper can also give you a clue as to whether baby is eating enough: A wet diaper every three to four hours is a good sign. Stools can be more variable: Some babies poop every time they eat, others just once a day.

But at the end of the day, “how baby is acting and growing are the most important [signs],” Trachtenberg says. By measuring baby’s weight gain, your pediatrician will be able to tell if baby is thriving. Babies usually gain about half an ounce to two ounces per day for the first three months, says Meryl Newman-Cedar, MD, a pediatrician and clinical instructor of pediatrics at Weill-Cornell Medical Center. But keep in mind that the big picture is more important than any single weigh-in. “In general, you want to see baby’s height and weight basically follow his or her own growth curve,” she says.

Newborn Feeding FAQs

Should I wake baby for feedings?
“I tell parents not to wake a sleeping baby,” Trachtenberg says—at least once baby has gained back his birth weight and is continuing to feed every three to four hours during the daytime. (It’s normal for newborns to lose weight in the first few days of life and then gain it back.)

Should I wake baby if she dozes off during a feeding?
Some doctors say yes. “When that happens, baby eats so slowly that one feeding runs into the next feeding time—and parents find themselves with little time for anything else,” Newman-Cedar says. Try slightly undressing baby, tickling her feet or patting her bottom to get back on task.

Is baby eating too much?
While baby is naturally aware of when he’s hungry and when he’s had his fill, it’s possible for well-meaning adults to coax baby into overeating, especially from a bottle. To avoid overfeeding, watch for signs baby is full, such as turning his head, pushing the bottle away or fussing. And don’t be too focused on making sure baby finishes every last drop. Trachtenberg suggests putting no more than a half-ounce more than you expect baby to eat at each feeding in a bottle. If baby drains that too, you’ll know it’s time to add a little bit more. But go slowly: Try pausing halfway through the bottle, sitting baby up and burping him—then see if he actually wants more.

Should I worry that baby is losing weight?
Don’t stress: It’s totally normal for newborns to actually lose weight in the first few days of life—up to 7 to 10 percent is considered acceptable. Beyond that, your doctor may advise you to supplement with formula to ward off dehydration and low blood sugar.

If baby isn’t getting enough calories, you’ll start to see a lag in growth, Newman-Cedar says. It starts with a decrease in baby’s weight, then length and lastly head circumference, since the body prioritizes the brain when nutrients are scarce. But when it comes to baby’s growth, bigger isn’t necessarily better. It’s all about the growth curve. “If you have parents who are thin and the kid is in the 10th percentile, that’s probably normal for that child,” Newman-Cedar says.

Call your pediatrician if baby has a fever; is lethargic, refusing to eat or vomiting a lot in between feedings; isn’t urinating at least every four to six hours; or if baby’s urine is very concentrated (dark yellow).

Photo: Thanasis Zovoilis / Getty Images