When can babies have water?

It feels like it should be the safest thing in the world, so this one surprises a lot of parents: babies under 6 months should not be given water, and even after that it stays a small supporting act, not a main drink. Here is the simple version by age.

Before 6 months: no water needed

Breast milk and formula are mostly water and provide complete hydration, even in hot weather. A young baby does not need, and should not have, extra water. Their kidneys cannot handle it, and too much can dangerously dilute the sodium in their blood (a condition called water intoxication). It also fills a tiny tummy and displaces the calories they need to grow. If you ever think your baby needs water for a medical reason, ask your pediatrician first.

Around 6 months: small sips with meals

Once solids start, you can offer small sips of water in a cup with meals. Think a few ounces across the day, not a bottle of it. This is as much about learning to drink from a cup as it is about hydration. Milk feeds still provide most of what your baby needs.

Any cup works: open, straw, or a sippy training cup are all fine at this age. Open and straw cups are worth practicing with early, and the goal that matters most is moving on from bottles by around 18 months.

12 months and up

After the first birthday, water can become a normal, freely offered drink alongside whole milk. Water and milk are the two drinks toddlers actually need. Juice is not necessary, and if you offer it at all, keep it small and with a meal.

A quick summary

Under 6 months: no water, milk only.
6 to 12 months: small sips with meals, from a cup.
12 months+: water freely, alongside whole milk.

Frequently asked questions

When can babies start drinking water?

Small sips of water can begin around 6 months, once your baby starts solids, offered in a cup with meals. Before 6 months, babies do not need water. Breast milk or formula gives them all the hydration they need, and extra water can be harmful.

How much water can a baby have?

From 6 to 12 months, just a few ounces a day, sipped from an open or straw cup alongside meals. It is for practice and a little extra hydration, not a main drink. Milk feeds still do the heavy lifting. From 12 months, water can flow more freely.

Why is too much water dangerous for young babies?

A young baby’s kidneys cannot handle large amounts of water. Too much can dilute the sodium in their blood, a condition called water intoxication, which can cause seizures and be life-threatening. Extra water also fills a small tummy and crowds out the calories and nutrients they need from milk.

What kind of cup should I use for water?

Open, straw, and sippy training cups are all fine to start around 6 months. Many feeding therapists like getting practice with open and straw cups early, and the bigger goal everyone agrees on is moving away from bottles by around 18 months. Start with tiny amounts and expect plenty of spills at first.

Sources

😋 🤢

Track it in YummyYucky

Log first tries and reactions, with an automatic allergen tracker when a food needs one, all in one place you can share with your pediatrician.

Start tracking for free

Last updated September 2026. Next review December 2026. How we write these: built from current published guidance from the AAP, CDC, FDA/EPA, NIAID, WHO, and other pediatric and public-health authorities, with sources cited on the page. See our editorial and medical policy for how we research, source, and update these, and how we double-check the food advice.

This is general information, not medical advice, and is not individualized for your baby. Always talk to your pediatrician about your baby's diet, introducing allergens, and any reaction. In an emergency, contact emergency services.

Some links in our guides are affiliate links: if you buy through them we may earn a small commission, at no extra cost to you. We only suggest things we'd actually use, and it never changes our guidance.