Expressed breastmilk: How much does your baby need?

I am feeding my baby expressed breastmilk. I have heard that there is a formula for figuring out what she needs (approximately) each day. Is this true, and if not, how can I determine how much to feed my one month old, who weighs 12 pounds?


Kathy Kuhn

Kathy Kuhn is a registered nurse who has been working with breastfeeding families since 1981. She has been an International Board Certified... Read more

There is a mathematical formula commonly used for calculating how much expressed breastmilk to feed a baby at each feeding. Though this mathematical formula is commonly used I could not find a reference for it in any breastfeeding resource and found some variation among methods. Understand that this calculation will only provide a very rough estimation of what your baby needs at each feeding and should not be used as a hard and fast rule.

When feeding expressed breastmilk you should follow your baby's cues to determine both the timing and amount of each feeding. You should also ask your pediatrician for an expected 24 hour total intake of breastmilk if your baby is only getting expressed breastmilk and not taking milk directly from the breast at all. It is my understanding that this mathematical formula does not work as well as the baby gets older and bigger.

To calculate the approximate range for the number of ounces of expressed breastmilk to provide per feeding use the following mathematical formula:

Take your baby's weight in pounds and multiply it by two and a half to three times. Then, divide this number by the total number of feedings per day to arrive at the approximate feeding amount, in ounces, for each feeding.

In your case this would be baby's weight (12) times either two and a half, equalling 30 (ounces) or three times, equalling 36 (ounces). Then divide this number by the total number of feeds per day. For example, if your baby has ten feedings per day, he or she would have between 3 and 3.6 ounces at each feeding.

Babies commonly take a variety of amounts at each feeding. I tell mothers to store their milk in small increments at first, usually one or two ounce increments. That way it is easy to tailor each feeding amount to the baby's need. Because the milk is stored in small units, it is easy to thaw and warm and there is little waste.

As your baby becomes more accustomed to taking expressed breastmilk, you may notice he or she takes a similar amount at each feeding. At that point it may be easier to store in that amount. I would still recommend storing some breastmilk in smaller increments for those times when your baby wants a little more as she grows, or as a little snack.

If you are exclusively providing expressed breastmilk, you may want to consider providing at least some of the feedings at the breast to take advantage of some of the health benefits that are only received by direct breastfeeding. To learn more about how to accomplish this if you are having trouble getting the baby on the breast, contact a local board certified lactation consultant for assistance.

Congratulations for striving to give your baby the most perfect nutrition.


The Breastfeeding Answer Book, La Leche League International, Schaumburg, IL, 1997, 210, Mohrbacher, N and J. Stock.


Watch Video: Breast Pumping

Need Advice?
Get answers from iVillage experts and other moms just like you!
Question Details
  1. Pick a subject:
Connect with 1,039,394 members just like you
Share your knowledge, ask questions.