When Should Babies Start Drinking Water?

Many parents wonder when it’s safe to offer water to their baby. The answer is simple: babies shouldn’t drink water until around six months old. This is because breast milk or formula provides all the fluids and nutrients little ones need for healthy growth.

Starting water too soon can cause health problems, like upsetting your baby’s balance of minerals. Waiting until they’re about six months old, when they start eating solids, helps protect their health and supports steady development. This guide walks you through when and how to introduce water, so you can feel confident about your choices.

Why Newborns and Young Infants Should Not Drink Water

When babies are tiny, their bodies have special needs that most adults don’t realize. Giving water before six months can seem harmless, but it can actually cause problems for your baby. Let’s take a closer look at why breast milk or formula is the only thing little tummies should have in those early months—and why water just isn’t needed or safe for newborns and young infants.

Nutritional Sufficiency of Breast Milk and Formula

Photo by Helena Jankovičová Kováčová

Breast milk and infant formula are perfectly balanced to meet your baby’s every need. Both contain about 85-87% water, which keeps babies fully hydrated, even in hot weather. The rest is a blend of:

Carbohydrates, mainly lactose for energy and brain growth
Fats like DHA and ARA for healthy brain and eye development
Easy-to-digest proteins that won’t stress tiny kidneys
Naturally occurring vitamins and minerals for bones, growth, and immunity

Both breast milk and formula are rich in immune factors. These natural defenders help fight off germs and protect against infection. The composition of breast milk even changes as your baby grows, always keeping up with what they need.

Babies are born with small tummies and immature kidneys. Offering water can fill them up quickly, risking them missing out on essential calories. Every drop your baby drinks should be packed with nutrition, which is why breast milk and formula are the only fluids recommended under six months.

Risks of Early Water Introduction

Giving water to a newborn may sound simple, but their bodies just aren’t ready for it. Here’s why:

Immature kidneys: Your baby’s kidneys are still learning how to process fluids. Too much water can overwhelm them, leading to water intoxication.
Diluted sodium levels: Water can lower your baby’s sodium in the blood, a dangerous condition called hyponatremia. Symptoms can include fussiness, sleepiness, seizures, and in severe cases, coma.
Nutrient loss: Water can “crowd out” the calories, fats, and minerals babies need to grow. Even small amounts can quickly tip the balance.
Less hunger for milk or formula: Babies drinking water may want less milk or formula, meaning they’re getting fewer nutrients.

How can parents check if baby is hydrated? Count wet diapers. Most newborns need 6-8 per day with pale, light-colored urine—signs that baby is getting enough to drink from breast milk or formula alone.

Common Myths and Cultural Practices About Baby Water Intake

Many cultures have traditions or advice handed down through families about babies and water. Here’s what you might hear—and what science says:

Myth: Babies need extra water in hot weather.
- Fact: Breast milk or formula keeps babies perfectly hydrated, even in summer.
Myth: Water calms down colic or fussiness.
- Fact: Water doesn’t soothe colic and may actually cause discomfort or risk.
Myth: It’s okay to “thin out” formula with water.
- Fact: Diluting formula is dangerous and can disrupt your baby’s sodium and nutrient balance.
Myth: All people drank water as babies and turned out fine.
- Fact: Many health risks weren’t recognized or understood in the past. Today, we know more about how babies’ bodies work.

Sometimes, small sips of water are given for rituals or family traditions. However, for health and safety, the best practice is to wait until your child is about six months old and has started solid foods before offering any water.

If you ever wonder whether your baby is getting enough fluids or if you think your baby has had too much water, reach out to your pediatrician right away.

When and How to Safely Introduce Water to Babies

Moving from exclusive breastfeeding or formula to adding water is a key milestone for your baby. The right timing and approach can help support healthy habits and prevent health concerns. Here’s what parents need to know about safely starting water, how much to offer, and the best methods to prepare and serve it.

How Much Water to Offer and When

Less is truly more when starting water. The smallest amounts go a long way toward teaching your child to drink while keeping nutrition on track.

Start with:

1 to 2 ounces (30–60 mL) at a time, once or twice a day
Offer water with meals instead of replacing milk or formula feeds
Watch for fullness—don’t push your child to finish more water than they want

From 6–12 months, up to 4–8 ounces (about 0.5–1 cup) per day is enough. Most of their hydration still comes from breast milk or formula. After their first birthday, you can gradually increase water as your child’s diet shifts more toward solids.

It’s also helpful to:

Offer water during mealtimes to help wash down solids and practice sipping
Skip water between feeds to make sure milk or formula remains their main drink

Safe Water Preparation and Serving Methods

Safety comes first when serving water, especially for babies under one year. Tap water can contain lead or germs in some areas, so preparation matters.

For babies under 12 months: Boil tap water for at least one minute, then let it cool before using. Always use clean, sterilized cups or bottles.
Home filtration: If your tap water has a known risk (lead pipes, old plumbing, well water), use filtered or bottled water marked as safe for infants.
Never serve carbonated, sweetened, or flavored water. These can lead to dental problems and poor drinking habits.
Don’t force large amounts. Too much can cause water intoxication, leading to a dangerous drop in sodium levels.

As your child gets older and your local water supply is tested and safe, boiling is no longer needed after their first birthday.

Progressing from Bottle to Cup

Teaching your baby to drink from a cup is just as important as the water itself. Open cups or straw cups are best, starting around six months.

Photo by Juliia Abramova

The steps are simple:

Give sips from an open cup, straw cup, or a free-flow beaker at each meal.
Hold the cup and guide their hands at first.
Expect spills—messy learning is part of the process.

By age one, most children can begin using a cup without much help and can start to phase out bottles. This supports healthy oral development and builds independence.

Practice and patience make all the difference. Celebrate small wins, and remember: every sip is a sign your baby is growing.

Health Risks Associated With Giving Water Too Early

Giving water to babies before six months may seem like a small choice, but it can lead to serious health problems that most parents aren’t told about. Babies’ bodies don’t handle fluids the way older kids or adults do. Even a small amount of extra water can put your baby at risk.

Their kidneys are immature and can’t remove water as efficiently. Added water can tip the balance of important minerals like sodium, and may even reduce their desire to drink breast milk or formula—their main source of nutrition. Let’s look at how water intoxication and hyponatremia can develop, and the warning signs every parent should know.

Understanding Water Intoxication and Hyponatremia in Infants

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Water intoxication occurs when a baby drinks too much water, causing the level of sodium in their blood to drop dangerously low—a condition known as hyponatremia.

Why does this happen so easily in babies?

Their kidneys are still developing, so they can’t filter excess water properly.
Breast milk and formula already provide the right amount of water babies need.
Extra water dilutes sodium and other electrolytes in the blood.

What can result from this imbalance?

Low sodium (hyponatremia) can cause cells to swell—including brain cells.
Swelling in the brain can trigger seizures, brain damage, and in rare cases, coma or death.

Research and medical reports have described dozens of cases where infants suffered seizures, confusion, and swelling—all after drinking too much water or diluted formula. Bottled water marketed to infants is not a safe choice either: even “baby” water can cause problems if used instead of breast milk or formula.

The risks don’t stop there:

Water fills up tiny stomachs, so babies drink less milk, miss key calories, and lose out on nutrients.
Poor weight gain and problems with growth become more likely.
Replacing nutrient-rich milk with plain water interrupts healthy brain development.

Medical groups like the American Academy of Pediatrics, WHO, and UNICEF agree: skip water until your baby starts solids, and use formula or breast milk only for hydration.

Signs and Symptoms to Watch For

Knowing the warning signs of water intoxication and hyponatremia can help you act fast if something seems off.

Some symptoms are subtle while others are alarming. Watch for:

Sudden fussiness or extra sleepiness
Unusual irritability
Weakness or a limp feeling baby
Swelling (especially around the face)
Decreased body temperature
Fewer wet diapers than normal

Serious signs—call your doctor or local emergency number right away if you see:

Seizures (jerking movements, twitching, staring spells)
Trouble breathing
Vomiting with no clear cause
Trouble waking your baby, or if they are hard to arouse

A helpful checklist for parents:

Track feeding: If your baby is taking water and drinking less milk, monitor them closely.
Count wet diapers: Fewer than six in 24 hours is a warning sign.
Monitor growth: If your baby isn’t gaining weight or seems to shrink their feeds, talk to your doctor.

Never hesitate to reach out to your pediatrician if your baby isn’t acting like themselves or if you suspect they’ve had too much water. Quick action is key—the risks of early water are real, but they’re also preventable.

Special Circumstances and Common Concerns

Most of the time, the rules about water for babies are simple: no water before six months. But life isn’t always so clear-cut. Parents often face special situations, like a baby getting sick or living through a heatwave. Cultural beliefs and worries about formula mixing also pop up frequently. It helps to know what trusted health authorities recommend in these moments, so you can keep your baby healthy while respecting your family’s unique style.

Hydration in Hot Weather or During Fever

Photo by Nahmad Hassan

When the air feels like an oven or your baby spikes a fever, it’s natural to worry about dehydration. You might wonder if you should reach for a bottle of water. Here’s what experts like the World Health Organization and top pediatricians say:

Babies under six months: Stick to breast milk or formula, even in very hot weather or when baby feels unwell. Both keep your child hydrated better than water alone.
During a fever: Increase breastfeeding or formula feeds. These fluids are better balanced for your baby than water and supply needed calories for recovery.
Check diapers: The best clue your baby is hydrated is steady wet diapers (at least six per day) with light yellow urine.
Older infants (over six months): Offer small sips of water, especially when it’s hot or your child is ill, but milk/formula should still be the main drink.

If dry lips, fewer wet diapers, or sluggishness appear, call your pediatrician. For older babies and toddlers with vomiting or diarrhea, your doctor may suggest an oral rehydration solution.

Considerations for Formula-Fed Infants and Water Use in Formula Preparation

Mixing up a bottle might seem easy, but water safety makes a big difference for formula-fed babies.

Always follow formula instructions exactly. Too much water can dilute precious nutrients and risk water intoxication.
Before six months: Boil tap water and let it cool before mixing with formula, even if your water supply is considered safe. This kills germs and gets rid of chemicals like lead.
After 12 months: Most healthy babies can have cooled, unboiled tap water if your local supply is safe.
Never add extra water to “stretch” formula. This old trick can lead to seizures and slows healthy growth.
Bottled water can sometimes contain too many minerals for babies, so only use it if instructed by your doctor or if it’s labelled for infant use.

If you have concerns about water quality in your area, talk with your doctor or a local health authority.

Cultural Beliefs and Frequently Asked Questions

Family traditions run deep, and water is often part of generations-old baby care advice, especially in certain cultures and communities.

Common beliefs and questions include:

“My relatives say babies need water in hot weather or for ceremonies—is it really unsafe?”
“Some caregivers say water will calm a crying baby, is this true?”
“What drinks can my baby have before their first birthday?”

Here are some trusted answers to these common questions:

Hot weather and rituals: The need for water hasn’t changed with the weather—breast milk or formula hydrates best. For rituals, speak with your doctor for safe ways to honor tradition.
Water for fussiness: Water doesn’t treat fussiness or colic. Instead, stick with frequent feeds and calming routines.
Safe drinks before 12 months: Breast milk and formula only—no fruit juice, herbal teas, cow’s milk, or sweet beverages.

Keeping grandparents and relatives in the loop helps everyone stay on the same page. If you feel pressure to offer water early, share your doctor’s guidance or bring them to a checkup for a group conversation.

When in doubt, trust your instincts and reach out to your pediatrician. You know your baby best, and combining medical advice with family support leads to the healthiest choices for your growing child.

Best Drinks for Babies After One Year

Toddlerhood is a time for big changes. Suddenly, your little one wants to do everything themselves, including what they eat and drink. Around their first birthday, your baby’s diet shifts away from breast milk or formula being the main source of nutrition. Drinks become a key part of this transition. Choosing the right beverages supports growth, brain power, and healthy habits that last.

Introducing Water as a Primary Drink

After your baby’s first birthday, water becomes the go-to drink. Simple, refreshing, and perfectly hydrating, plain water meets your toddler’s daily fluid needs. It doesn’t fill them up with empty calories or set the stage for a sweet tooth. Most health experts agree: water and plain dairy milk are all your toddler needs.

Photo by Vanessa Loring

Here’s what to keep in mind when it comes to drinks after the big “one”:

Water: Serve throughout the day, especially with meals and snacks. About 1 to 4 cups (8–32 oz) a day is typical, depending on your child’s activity, the weather, and their diet.
Milk: Whole dairy milk is perfect after age one (unless your pediatrician says otherwise). Toddlers need the healthy fat from whole milk for brain development—about 2–3 cups (16–24 oz) daily is enough.
Breast milk: If you’re still breastfeeding, keep going as long as you and your child want—it’s still a healthy source of nutrition and comfort.
Fortified soy milk: Only if cow’s milk isn’t an option due to allergy or intolerance. Choose unsweetened, calcium-fortified versions.

Offer water in an open cup or a straw cup instead of a bottle. This boosts oral development and independence. It also clears sticky foods from their teeth, and if your water has fluoride, it gives extra dental protection.

Drinks to Avoid for Babies and Toddlers

Many drinks in the grocery aisle look “kid-friendly,” but that doesn’t make them a smart pick for your one-year-old. Avoiding sugary, sweetened, or unnecessary beverages now can help prevent lifelong habits tied to weight gain, tooth decay, and even picky eating.

Skip these common drinks for babies and toddlers:

Fruit juice: Even 100% juice is high in sugar and low in fiber. It can lead to tooth decay and crowd out appetite for healthier foods. For children under two, keep it off the menu.
Flavored or sweetened milks: Chocolate, strawberry, and vanilla milks add unwanted sugar and calories, promoting a strong preference for sweets.
Plant-based milks (almond, oat, rice, coconut): Except for fortified soy milk, most lack the right mix of nutrients for growth.
Toddler “transition” drinks or formula: These are heavily marketed, but usually unnecessary if your child eats a balanced diet with milk and solids. They add cost without proven benefit.
Sodas, sports drinks, flavored waters: Packed with sugar, acids, and sometimes caffeine. These offer nothing helpful for growing bodies.
Caffeinated drinks (tea, coffee, energy drinks): Caffeine isn’t safe for toddlers and can disrupt sleep, irritate, and upset their stomachs.
Unpasteurized milk or juice: These may carry germs that are dangerous for young children.
Herbal teas, honey-sweetened drinks: Risks include allergies, bacteria, and unpredictable ingredients.

A quick toddler drink checklist:

Stick with plain water and plain whole milk.
Avoid “treat” drinks, even on special occasions.
Read labels closely—avoid added sugars, syrups, and unnecessary additives.

Focusing on these simple choices helps your toddler develop a healthy relationship with drinks—and gives them the best start for a strong, thriving childhood.

Conclusion

Babies under six months don’t need any water. Breast milk or formula is enough to meet every need in those first months, including hydration. Waiting until your baby is eating solids—usually around six months—gives their body time to mature and keeps risks like water intoxication or poor weight gain at bay.

Once your child reaches this stage, start with only small sips, and focus on keeping milk or formula as their main drink until they turn one. Always use safe water, and remember, a trusted pediatrician is your best resource for any questions or unique concerns.

Safe hydration habits start early and last a lifetime. Thanks for reading—share your experiences or questions below to help other parents learn and feel confident too.

When Can Babies Drink Water? Safe Guide for Parents | 2025 Pediatric Advice