How and when to transition to milk from formula or breast milk


It seems like just when you’ve gotten the hang of feeding your infant and have a good routine going, it’s time to start thinking about the next step in their feeding journey. So when exactly are babies supposed to transition off baby formula? And how do you do this? What about switching from breast milk? And how long can babies drink from a bottle anyway? Let’s dive into all your transitioning questions.

How long should babies have only breast milk or formula?

Before we talk about the weaning off of baby formula or breast milk, let’s review when and how to start the transition to solid foods in younger infants and then to milk for older infants.

For the first 4 to 6 months of life, breast milk or formula are all your baby needs to grow and develop. During this time infants will nurse or take a bottle frequently. Breastfed infants nurse about 8 to 12 times per day and formula fed infants take about 6 to 8 bottles per day.1

Starting solid foods is an exciting time for parents and babies. By 4 to 6 months, infants are taking anywhere from 28 to 45 ounces of breast milk or formula per day.1

Why introducing a cup is so important for your baby

Although babies usually won’t stop using bottles entirely until they are between 12 and 18 months old, it’s a good idea to start introducing cups when they are about 6 months old— just around the time they are starting solid foods.3

What’s so important about a cup instead of a bottle? This is a great question. Since we all know that giving a 6 month old a cup is a messy idea, there must be a good reason for recommending it. And there is!

Bottles can cause tooth decay in infants and toddlers, so switching to a cup as soon as infants are developmentally ready helps keep their teeth healthy.3 Bottles also allow babies to drink more milk than a cup, so may cause them to drink more than they need as they get older.4

You can start to introduce a cup by just letting your baby hold it before you give it to them with any liquid. Once they start drinking from the cup (with your help), you can start to introduce a sippy cup when they are 8 to 10 months old. Try using a sippy cup to replace one bottle per day (always the same one to keep a routine). Then each week you can change one more bottle to a sippy cup for a nice steady transition.3

What age do you transition off of baby formula?

Now that we have switching to a cup under control, let’s get down to the business of transitioning off your baby’s formula. One of the most common and important questions about this is what is the right age to do this? The answer: when your baby turns 1 year old (and not before, since babies should have only formula or breast milk to drink for the first year of life).3

Transitioning from baby formula to regular milk

What to transition to is also fairly simple. The answer: whole cow’s milk.5 It’s important to stick to whole cow’s milk because the fat helps with brain development.6 1-year-olds need about 16 ounces of whole cow’s milk per day.5

Children should keep taking whole cow’s milk until they are 2 years old (unless your baby’s healthcare provider suggests a different option) and should not switch to a lower fat option before then. After they turn 2 years old you can talk to your baby’s healthcare provider about what to do next.6

How to transition your baby to whole cow’s milk

The question of how to transition can be a little trickier. Some babies are able to transition with no issues— a sippy cup of formula one day is replaced by a sippy cup of whole cow’s milk the next day- done! Other babies need a slower transition to whole cow’s milk to adjust to the new taste. Here are ways you can help:5

  • Start by putting some whole cow’s milk in their cereal
  • Mix a small amount of whole cow’s milk into their formula and slowly increase the portion of whole cow’s milk and decrease the portion of formula as they adjust
  • Warm up the cow’s milk if your baby is used to warm formula (but just like formula, never use a microwave to warm milk)

Remember, after your baby turns 1 year old, whole cow’s milk is just a drink for them and not a whole meal the way formula or breast milk were. They should be eating a good variety of foods by now.6

Weaning off breastfeeding

Unlike formula, it’s perfectly fine to keep breastfeeding your baby after they turn 1 year old. As a matter of fact, there is no age when a baby needs to stop breastfeeding, and the decision to continue or to wean is really based on what feels and works best for you and your baby.7

If you have only ever breastfed, weaning for you may mean switching to pumped breast milk, formula, or whole cow’s milk depending on your baby’s age and what works best for you both. If your baby is 6 months old or younger, you should transition to a bottle using formula or pumped breast milk. If your baby is older than 6 months, you can transition to a bottle or cup, as discussed above, using formula or pumped breast milk. Solid foods can be introduced as discussed above.7

Babies who wean off breast milk after they turn 1 year old can transition to whole cow’s milk just like a baby who takes formula. In this case, you can mix breast milk with whole cow’s milk to make the transition easier if needed.

Signs your baby may be ready to try solid foods include:

Be sure not to introduce solid foods before your baby shows signs of being ready because they may choke if they aren’t able to swallow the food. New foods can be introduced in any order, but stick to foods with one ingredient (like a single pureed fruit or vegetable). Leave 3 to 5 days between trying new foods so you can tell if your baby has an allergic reaction to any of them.2

  • They can sit independently with good head control
  • They show you they are interested in food by opening their mouth and leaning forward when offered food
  • They swallow food rather than pushing it back out when offered
  • They try to hold small objects and bring them to their mouth

The important facts when transitioning off of formula or breast milk

There are lots of transitions that take place with your baby’s eating and drinking during the first year of life. For the first 4 to 6 months they should only have breast milk or infant formula, nothing else. Once they show signs of being ready to try solid foods, you can begin slowly introducing these. This is also a great time to start introducing a cup. Once your baby turns 1 year old, they should transition off formula to whole cow’s milk and work on getting off the bottle entirely.

If your baby is breastfed, you can continue to breastfeed as long as you both like while introducing solid foods around 6 months old and formula or whole cow’s milk (depending on your baby’s age) once you are ready to stop breastfeeding. Remember to check in about your baby’s current feeding habits and your future feeding plans at every visit with their healthcare provider so you can stay on track and get all the advice you need along the way.


1- What is weaning and how do I do it? | National Institutes of Health

2- When, what, and how to introduce solid foods | Centers for Disease Control and Prevention

3- FAQ: baby bottle weaning | UCSF Benioff Children’s Hospitals

4- Stopping the bottle | Nemours KidsHealth

5- How do I transition from formula to milk? | California Women, Infants, and Children

6- Making the switch to cow’s milk for 1-year-olds | Children’s Hospital of Philadelphia

7- Weaning your child | Nemours KidsHealth

The content on this site is for informational purposes only and not intended to be a substitute for professional medical advice, diagnosis or treatment. Discuss any health or feeding concerns with your infant's pediatrician. Never disregard professional medical advice or delay it based on the content on this page.

The content on this site is for informational purposes only and not intended to be a substitute for professional medical advice, diagnosis or treatment. Discuss any health or feeding concerns with your infant’s pediatrician. Never disregard professional medical advice or delay it based on the content on this page.

Meet the Author

Morgan Leafe

Morgan Leafe, MD, MHA, is a medical writer and editor who is double board certified in Pediatrics and Clinical Informatics with 14 years of clinical experience caring for pediatric patients and their families. She specializes in writing both patient-facing and clinician-facing material.

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