When Can Babies Drink Water? The Answer May Surprise You!

Find out why babies shouldn’t have water for so long. Plus, learn how to introduce the beverage once it’s time.

Babies first food is liquid-- whether that's breast milk or formula. But you might be wondering: When can babies drink water? You may be surprised to learn most babies don't need water, and too much water can even be dangerous. Here's what you need to know.

Babies first food is liquid—whether that’s breast milk or formula, and most babies don’t start solids until they are six months old. But you might be wondering: When can babies drink water

In this post we’ll break it all down for you by answering:

When Can Babies Drink Water?

  • For babies 0-6 months: No supplemental water.
  • For babies 6-12 months: 2-4 ounces of water MAXIMUM. Most breastfed babies don’t need supplemental water—once you introduce solids you can introduce water for practice and play. Formula-fed babies may need a little bit more water, but no more than 4 ounces.
  • For babies and toddlers 1-3 years old: Many experts recommend 30-40 ounces of water, but that’s a lot for a toddler—especially if you’re still breastfeeding. Talk to your pediatrician about what’s right for your baby.

In formula-fed babies, a few sips of water can offset constipation caused by starting solids. For breastfed babies, a little bit of breast milk before or after a serving of solids can help with constipation brought on by starting solids, and is preferable to water. (source)

In the end, talk to your pediatrician about when is the best time to give water to your baby.

Is It OK to Give Water to a Newborn?

Healthy babies do not need extra water. Breast milk, formula, or both provide all the fluids they need. (source)

It may seem like there are certain circumstances that would call for baby drinking water, but small babies hydrate in other ways, and drinking water can actually be harmful to them. (Keep reading to find out how.) 

When Can Babies Drink Water? Composition of Breast Milk

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  • Breast milk is made up of 88 percent water, and is sufficient to keep your baby well-hydrated.
  • And most formula is made by mixing 1 level scoop of powder for every 2 fluid ounces of water, which is also plenty of water to keep baby hydrated.

During the first few days of life, supplementation of any kind interferes with the normal frequency of breastfeeding. “If the supplement is water or glucose water, the infant is at increased risk for increased bilirubin, excess weight loss, longer hospital stay, and potential water intoxication.” (source)

“If you dilute the formula with more water, it will contain fewer calories per ounce and not provide enough calories for your baby to thrive,” — Dyan Hes, MD, Gramercy Pediatrics in New York.

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The Dangers of Giving a Newborn Water

So babies don’t need to drink water, but what’s the harm in it after those first few days? You may be surprised to learn that giving an infant too much water is actually detrimental. Here are the rare, but dangerous results of too much water:

  • Dehydration: It sounds counterintuitive, right? But because a young infant’s kidneys aren’t developed enough to process supplemental water, it can cause them to release excess sodium and water into the urine, which can affect brain activity and lead to dehydration. (source/source)
  • Malnutrition: Babies who are given water in place of breastmilk or formula fill their bellies up with non-nutritious fluid instead of the healthy calories they need. Too much water can cause your baby to not receive enough nourishment from nursing, and can contribute to low weight gain or failure to thrive. (source) In breastfeeding babies, supplementing with water can also decrease a mother’s milk supply.
  • Water intoxication: Too much water can be toxic to both breastfed and formula-fed newborns. This occurs when there’s an imbalance of sodium and electrolytes in the infant’s body. It can cause irritability, brain swelling, unresponsiveness, and even seizures. (source/source)

When is It Safe to Give Baby a Bottle of Water or a Sippy Cup?

A baby usually starts learning to sip from a cup at six to seven months. By about one year, baby can likely manage this on his/her own. (source)

Once baby has the hand-eye coordination to hold a cup and is ready to start slowly drinking water, here’s how to introduce a bottle of water or a sippy cup: 

  1. Use a cup with handles that has either a soft spout or a straw. Try this one.
  2. Support your baby in an upright position and always supervise. Baby may splutter and/or cough at first.
  3. Mimic the action. Studies show that babies learn by imitation.

It’s important to note that sippy cups should be considered a training tool to help a baby transition from a bottle or the breast to a cup—they are not intended for longterm use.

“Sippy cups were created to help children transition from a bottle to drinking from a regular cup, but they’re too often used for convenience,” says American Academy of Pediatric Dentistry (AAPD) President Philip H. Hunke, D.D.S., M.S.D. “When kids sip for extended periods on sugared beverages, they’re exposed to a higher risk of decay. Sippy cups should only contain water unless it’s mealtime.”

Once baby reaches his/her first birthday, they should be drinking from an open cup.

How to Introduce Water

Start off slowly! Like anything new, baby’s system needs time to learn how to process water. Try a little bit—like a cap-full of water—at a time. Wait and see how your baby reacts. And never use water as a meal replacement. If baby fills up on water, he/she won’t get enough calories from breast milk, formula, and/or solid food. Plus, this can wreak havoc on your milk supply before you’re ready to wean.

“From 6 to 12 months, babies do not need much water but introducing some in a bottle or sippy cup can help them get used to the taste (or lack thereof) and consistency of the liquid.” — Dr. Jennifer Shu, pediatrician, Children’s Medical Group

“Limiting water to about 2 to 4 ounces per day is the typical recommendation as babies make the transition from an all-liquid diet to one involving solids,” says Dr. Shu. Avid breastfeeding babies may need less or show no interest in drinking water. While “some babies may benefit from closer to 6 to 8 ounces per day (such as in the case of constipation or extremely hot and humid weather).”

After baby’s first birthday, he/she can drink water more freely, though the amount needed will vary based on whether or not (and how frequently) mama is breastfeeding.

“After 12 months of age, a good rule of thumb is to offer milk with meals and water at most other times for thirst.” — Dr. Shu

Talk to your pediatrician about how much water your child should be drinking each day. 


Like many things when it comes to raising children, there is no simple answer to the question when can babies drink water? How much water a baby can drink—and when—depends largely on the child’s main food source and can even vary based on the climate where you live. The above information should be treated as rough guidelines—always talk to your pediatrician about what’s right for your child.

How About You?

When do you start giving your baby water? What tips do you have for getting older babies and toddlers to drink water?

Genevieve Howland

About the Author

Genevieve Howland is a childbirth educator and breastfeeding advocate. She is the bestselling author of The Mama Natural Week-by-Week Guide to Pregnancy and Childbirth and creator of the Mama Natural Birth Course. A mother of three, graduate of the University of Colorado, and YouTuber with over 130,000,000 views, she helps mothers and moms-to-be lead healthier and more natural lives.


  1. Should we boil the water before giving them? Or is just being filtered okay? Thanks!

  2. My little guy is 9 months and we’ve been practicing drinking from an open cup that I hold for awhile which has been fine. Today I introduced the 360 cup which he figured out really quickly! Problem was everytime I took it away he would BAWL. Like tears level of crying. After a few moments he would go back to eating and be fine. But it has me wondering if I should be letting him drink more?? Any tips?

  3. Very educative….awareness prompt and inspiring. Thanks for this app

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