infant baby stomach size and growthOne of the biggest concerns of new parents (and new grandparents, aunts, uncles, and anyone in any way involved with your baby) is whether baby is getting enough to eat. While it’s easy to tell how much is going in with babies who are bottle-fed, the volume nursing babies take in is a mystery. Regardless of the feeding method, the size of your baby’s stomach may come as a surprise. “How do you know she’s getting enough?”
“He’s always crying. He’s hungry!”
“She needs to eat more than that, surely!”

Whether they mean to or not, some well-meaning people in your life can make you doubt yourself when it comes to whether your baby is getting the all-important “enough” to eat.

One of the most surprising things I heard when I watched the “Simply Breastfeeding” DVDs was the size of a baby’s stomach and how it grows during the first few weeks.

Days 1 and 2: The Size of a Thimble or Marble

Have you ever wondered why your body produces so little colostrum? Think about it: here’s “nature’s immunization,” something so important to your baby that it’s often referred to as “liquid gold.” Yet the volume of this fluid is miniscule. Can you guess why? It’s simple: a newborn’s stomach can only hold the volume equivalent of a thimble or a marble. On top of that, over the first two days, a newborn’s stomach does not – cannot – stretch to accommodate more. Many parents and nurses have found out the hard way that feeding a newborn an ounce or two of anything is an exercise in futility: when that much goes in, that much is going to come right back out. Spitting up in newborns is due to a number of factors, not the least of which is the size of their tiny tummies.

Your body knows that your baby’s stomach can only handle about 5 to 7 milliliters (think of a marble or thimble) of milk. Your body is smart, because it only produces as much colostrum as your baby can hold. The size of your baby’s stomach and the volume of your colostrum are matched, and frequent feedings (approximately 10 to 12 times each day) are normal.

Day 3: The Size of a Ping-Pong Ball or Your Baby’s Fist

Your baby’s stomach grows like gangbusters in the first three days until it’s about the size of a ping-pong ball or the baby’s fist (22 to 27 milliliters). By this time, your milk probably hasn’t come in yet, so there’s really no point in your baby’s stomach capacity growing any faster than that. On the third day, feeding your baby anywhere from eight to 12 times each day is normal
It’s better to feed your baby several small meals rather than fewer, larger ones. First, because your baby’s stomach simply can’t hold that much, and second, because long nursing sessions at this stage can actually lead to sore nipples. Frequent nursing sessions, not lengthy ones, are the way to go at this stage. The time for long nursing sessions will come later, when your baby’s stomach has grown large enough to accommodate larger volumes of milk.

Day 10 or So: The Size of a Large Egg

By the time your milk has come in and the supply is established, let’s say day 10, your baby’s stomach can handle a volume equivalent to 60 to 81 milliliters, which is roughly the size of a large chicken egg. And how large is an adult’s stomach? You may be surprised, but it’s only about the size of your fist, a grapefruit, or a softball.

“Enough” Is Relative

So now you know that “enough” to eat is quite relative. Your body is remarkable: it has produced a baby and will nourish your newborn with the right amount of colostrum and the right amount of breast milk, once it’s come in.



Silverman, WA, ed. Dunham’s Premature Infants, 3rd edition. New York: Hoeber, Inc., Medical Division of Harper and Brothers, 1961, p. 143–144.

Stomach Capacity of the Newborn

The Size of a Newborn’s Belly

Your Newborn’s Stomach – Days 1 to 10

Photo © Roijoy –

About the Author

Laurel Haring is a writer. She lives with her family in Wilmington, Delaware, and posts semi-regularly to her blog, Let Me Say This About That. aurel wishes she had known then what she knows now about the size of her babies’ stomachs – it would have saved her a lot of worry and prevented a number of gray hairs.