When Can Babies Have Water? How Much by Age

The short answer

Water by age: before 6 months, milk feeds cover all fluid needs and no water is needed; from around 6 to 12 months, offer sips of water from an open cup with meals, about 4 to 8 ounces a day in total; from 12 months, water and milk become the main drinks.

Water starts when solids start: from around 6 months, offered in small sips from a cup with meals. Before that, breast milk or formula covers everything your baby needs to drink. The AAP’s HealthyChildren.org puts a number on it: “Around 6 months, you can start offering your baby a little bit of water (4-8 oz/day, 0.5-1 cup/day).” That is the whole prescription. A few sips at mealtimes, not bottles of water between them.

Why water waits for solids

For the first half year, milk feeds are both food and drink, and they are complete. Neither the AAP nor the NHS suggests water before solids begin. A young baby’s stomach is small, and water takes up space without bringing any nutrition with it; what a baby drinks in water, they tend not to drink in milk. The WHO marks the turning point the same way it marks solids themselves: “Around the age of 6 months, an infant’s need for energy and nutrients starts to exceed what is provided by breast milk,” which is when additional foods, and sips of water alongside them, enter the picture.

If it is very hot, or your baby is unwell, the answer under 6 months is more milk feeds, not water. If you feel your baby needs extra fluids for any reason at that age, that is a question for your pediatrician rather than the tap.

From 6 to 12 months: sips with meals

Once meals begin, water has a job: it lets your baby practice a new skill, it accompanies food, and it does both in small amounts. The NHS frames it exactly that way: “Once your baby has started to eat solid foods (from around 6 months) you can offer them sips of water from a cup or beaker with meals.”

Keep the AAP’s range in mind as a day’s total, not a target to hit: 4 to 8 ounces, which is half a cup to one cup. Milk feeds are still doing the heavy lifting for nutrition at this age, and our guide to the milk-and-meals balance from 6 to 12 months shows how the two fit together week by week. A pleasant side effect: those mealtime sips also help keep stools soft as fiber enters the diet, something we cover in our post on constipation after starting solids.

The cup matters more than you would think

This is the part most parents hear last: the drinking vessel is itself a skill decision. The NHS advises: “Using an open cup or a free-flow cup without a valve will help your baby learn to sip and is better for your baby’s teeth.” Valved spill-proof cups ask a baby to suck, which is the skill they already have; open and free-flow cups teach sipping, which is the skill they are building. Expect spills, offer help steadying the cup, and treat the mess as tuition.

What about juice?

Juice is not part of the picture in the first year. The NHS is direct about it: “Babies under 12 months do not need fruit juice or smoothies. If you choose to give these to your baby, dilute the juices and smoothies (one part juice to 10 parts water) and limit them to mealtimes.” Whole fruit at meals brings the same flavors with the fiber still attached, so there is nothing an 8-month-old is missing by skipping the juice aisle.

A note before you go

This is educational guidance drawn from published feeding resources, not medical advice, and it cannot account for your baby’s individual situation. Fluid needs change with illness, heat and medical conditions, and questions about hydration, wet diapers or fussiness at feeds belong with your pediatrician, who knows your baby’s story.

In the Miriel app, the Starting Solids program (Beta) builds a “what to feed today” plan from your baby’s own log, with the AAP, CDC, WHO and NIAID guidance behind each recommendation cited in-app, so you can read the source yourself. Start with our starting solids hub.

References

American Academy of Pediatrics. Recommended Drinks for Children Age 5 & Younger. HealthyChildren.org. https://www.healthychildren.org/English/healthy-living/nutrition/Pages/Recommended-Drinks-for-Young-Children-Ages-0-5.aspx
NHS. Drinks and cups for babies and young children. NHS. https://www.nhs.uk/baby/weaning-and-feeding/drinks-and-cups-for-babies-and-young-children/
World Health Organization. Infant and young child feeding. WHO Fact Sheets. https://www.who.int/news-room/fact-sheets/detail/infant-and-young-child-feeding