How Much Breast Milk Should You Put in a Bottle?

How to Figure Out What Your Baby Needs

How To Calculate The Amount Of Breast Milk To Put In A Bottle For Your Baby
How much breast milk should you put in a bottle?. Ray Moller/Dorling Kindersley/Getty Images

How Much Breast Milk Should You Put in a Bottle?

If you breastfeed, you don't know how much breast milk your baby is actually getting each time she nurses. So, if you're not going to put her to the breast for a feeding, how do know how much breast milk to put in a bottle?

How to Calculate the Amount of Breast Milk Your Baby Should Get in a Bottle 

You want to make sure that you're not overfeeding your baby when you give him a bottle, so here's a 3-step breast milk calculation that can help you figure out approximately how much breast milk your baby should take at each feeding.

#1. Convert Your Baby's Weight into Ounces

One pound equals 16 ounces, and don't forget to add in those extra ounces! So for example: If your baby weighs 8 pounds 4 ounces, you convert 8 pounds to ounces (8 x 16 = 128) then add the 4 extra ounces (128 + 4= 132). So, your baby weighs 132 ounces.

If you use kilograms, multiply your baby's weight in kgs by 35.2 to get ounces. For the example above 3.74 kg x 35.2 = 132 ounces.

#2. Divide by 6

Take your baby's weight in ounces and divide that number by 6 (132 / 6 = 22). This number represents how many ounces of breast milk that your baby should be getting in one day. Based on the weight above, this child should be taking in about 22 ounces of breast milk in a 24 hour period.

#3. Divide by 8

Now you need to take the total number of ounces per day and divide it by how many feedings your baby will get each day. A newborn or young infant should be eating at least every 3 hours which is 8 times a day.

So, take the number you just calculated and divide it by 8 (22 / 8 = 2.75 ounces).

If you prefer milliliters, 1 ounce = 30 ml. 

In this case, the baby should be taking approximately 2.75 ounces (82.5 ml) of breast milk at each feeding. So, you can put 3 ounces or 90ml of breast milk in the bottle to feed a baby who weighs 8 pounds 4 ounces.


Remember, It's Just an Estimate

Now, this is a recommendation and the amount of breast milk that your child should be getting at a minimum of every 3 hours. However, he may be interested in having more than the calculated amount. Also, you will want to adjust these amounts as your baby grows and gains weight. If you have any questions or concerns about how much breast milk your child needs, talk to your baby's doctor. 

How Much Breast Milk Should You Put in a Storage Container?

If you will be collecting and freezing your breast milk to bottle feed your baby, it's better to store your milk in 2 to 4-ounce portions especially when your baby is younger and not taking large amounts of breast milk. Storing in smaller amounts prevents waste. It's easy to thaw an extra 2 ounces if you need it, but if you thaw and warm a container with 6 ounces of breast milk and your baby takes 4 ounces, then you have to throw away the extra. Once your child gets older and is taking more at each feeding, you can store larger amounts in each container.


Riordan, J., and Wambach, K. Breastfeeding and Human Lactation Fourth Edition. Jones and Bartlett Learning. 2014.

Edited by Donna Murray

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