When Can My Baby Drink Water?

Baby drinking water from a glass

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It's a hot summer day and you're parched, so naturally, you reach for a cold glass of water. This gets you wondering if your 3-month-old baby also needs some H20 to stay hydrated and beat the heat. While the intentions are well-meaning, if your baby is under 6 months old, you should not give them any water.

"Prior to 6 months, giving your baby water will take the place of either formula or breast milk, meaning they will not be getting the nutrition that they need," explains Krystyn Parks, a pediatric registered dietitian nutritionist and the founder of Feeding Made Easy.

When babies reach 6 months old, they can have a limited amount of water. However, water only becomes necessary for babies once they reach age one. Let's dig deeper into why babies should stick to breastmilk or formula during their first year of life.

Is Water Safe for My Baby?

It is not necessary or safe for a baby under 6 months old to have water. At this age, babies get all the hydration they need from breast milk or formula.

If you are concerned about your baby's hydration in hot climates, know that breast milk is composed of 80% water. When it is very hot out, or if you're worried that your baby is not getting enough fluids, feed them breast milk or formula on demand, rather than offering water. Not only is breast milk and formula mostly water, but they also offer many vital nutrients that water does not.

"Babies generally rely on a volume to tell them they have reached an appropriate amount of nutrition, so if you give them water, or really anything other than breast milk or formula, it can be hard for them to tell if they are getting what they need," notes Parks.

Water before 6 months is dangerous because babies may fill up on water instead of the breast milk or formula that they need nutritionally. This can lead to malnutrition, supply issues, and unintended early weaning. Unclean water is also a safety risk that can lead to diarrhea or infections.

Risks of Giving Baby Water Too Soon

Giving a baby water too soon is neither necessary nor safe. Water before six months of age may lead to a variety of problems for your baby.

Early Weaning

Breastfeeding works on supply and demand. If you are breastfeeding, your body continues to produce breast milk depending on how often your baby nurses, or how often you pump your breast milk.

If you give your baby water instead of breastfeeding them, you may unintentionally signal your body to produce less milk. Over time, this may lead to early unintended weaning.


Water is not always clean enough for a baby's digestive system and it may cause infections, making a baby sick and leading to diarrhea.

Diarrhea is problematic because it puts the baby at risk of dehydration. It also rids the body of nutrients found in breast milk or formula before they can be absorbed into your baby's system, potentially causing malnutrition.


Your baby needs the nutrients found in breast milk or formula for proper development, especially over the first six months of their life. Giving water to your baby can cause them to drink less breast milk or formula, preventing them from taking in the appropriate amount. This can lead to malnutrition.

"Water before 6 months can create an imbalance in their electrolytes and can decrease the amount of milk or formula they drink, taking away nutrients that are important for their growth and development," explains Aimee Tyler-Smith RD, BEd, a registered dietitian and lead dietitian at The Nest: Nutrition for Mama and Baby.

When and How to Introduce Water

At around 6 months, you can start introducing small amounts of water to your baby in an open cup or a straw cup. "You will have to assist your baby in using an open cup at this age. Usually, you help them bring it to their lips, count one, two, and then lower the cup," explains Parks.

Yes, we said an open cup or a straw cup, not a bottle or a sippy cup. "[This] will help them to develop important oral-motor skills, and will allow them to begin to learn how to drink from an open cup," notes Tyler-Smith.

What Amount of Water Should I Give My Baby?

Beginning at 6 months old, your baby can start to drink 4-8 ounces of water per day. Their intake should not exceed this until after their first year.

"They really don't need water at first, so it is more about learning to use a cup than it is about getting water," notes Parks. "The main goal is to teach them to drink water, preferably from an open cup, so that when they are weaned, they are able to appropriately hydrate themselves."

By age one, your baby needs to drink 8 to 32 ounces of water per day. All babies are different, so some will be content with closer to 8 ounces while others will drink closer to 32 ounces.

Amount of Water to Give Your Baby, Based on Age
 6 months to 1 year old  4 to 8 ounces per day
 1 to 2 years old  8 to 32 ounces per day

A Word From Verywell

Babies under six months of age should not be given water, as they get all the water they need from breast milk or formula. Even in hot and humid climates, do not feed your baby water before 6 months. Instead, offer more breast milk or formula if they seem thirsty.

You can start giving your baby water at 6 months old but stick to 4-8 ounces. At this point, the purpose of giving your baby water is to let them practice drinking it. At one year old, your baby requires water and they should have 8 to 32 ounces daily.

If you have any questions or concerns about your baby drinking water, reach out to their pediatrician.

6 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Choose Water for Healthy Hydration. American Academy of Pediatrics.

  2. World Health Organization. Breastfeeding.

  3. Daly SEJ, Hartmann PE. Infant demand and milk supply. Part 1: infant demand and milk production in lactating women. J Hum Lact. 1995;11(1):21-26. doi: 10.1177/089033449501100119.

  4. Thiagarajah JR, Kamin DS, Acra S, et al. Advances in evaluation of chronic diarrhea in infants. Gastroenterology. 2018;154(8):2045-2059.e6. doi: 10.1053/j.gastro.2018.03.067.

  5. American Academy of Pediatrics. Breastfeeding.

  6. American Academy of Pediatrics. Recommended Drinks for Young Children Ages 0-5.

By Elisa Cinelli
Elisa is a well-known parenting writer who is passionate about providing research-based content to help parents make the best decisions for their families. She has written for well-known sites including POPSUGAR and Scary Mommy, among others.