A 12-month-old needs roughly 4 to 8 ounces of plain water per day, alongside breast milk, formula, or cow’s milk. That’s about half a cup to one cup. The exact amount depends on how much milk your child drinks, whether they’ve started eating water-rich foods, and how hot it is outside.
Daily Water Intake at 12 Months
The CDC recommends 4 to 8 ounces of water daily for babies between 6 and 12 months old. At the 12-month mark, most children are transitioning to cow’s milk and eating more solid foods, which means their fluid needs shift. Water becomes a bigger part of the picture, but milk and food still provide most of their hydration.
This doesn’t mean your child needs to sit down and drink a full cup in one go. Small sips throughout the day, especially with meals and snacks, add up quickly. If your child is breastfeeding frequently or drinking a full serving of cow’s milk, they may naturally want less water, and that’s fine. The 4-to-8-ounce range is a guideline, not a prescription.
How Milk Fits Into the Equation
Once your child turns one, you can introduce whole cow’s milk. The recommended range is 16 to 24 ounces per day. Staying within that limit matters for two reasons: too much milk can crowd out solid foods that provide iron and other nutrients, and it can also reduce your child’s interest in drinking water.
Think of your child’s total fluid intake as a budget. Milk takes up the largest share, water fills the gaps, and together with moisture from fruits, vegetables, and other foods, your child stays well-hydrated without needing to track every ounce precisely.
What About Juice and Other Drinks?
The American Academy of Pediatrics considers 4 ounces of 100% fruit juice per day a reasonable option for children over 12 months, ideally served with a meal. But juice isn’t necessary. It offers no nutritional advantage over whole fruit, and the sugar content can contribute to tooth decay and extra calories. Plain water and milk are the only two drinks a one-year-old truly needs.
Avoid sweetened beverages, flavored milks, and plant-based milks (unless recommended for a specific dietary reason) at this age. Fluoridated tap water has the added benefit of supporting developing teeth.
Practicing With a Cup
Around 12 months is the ideal time to start phasing out bottles and introducing cups. You can use a sippy cup with a simple spout (no valve), a cup with a straw, or an open cup. Many kids do surprisingly well with an open cup at this age, even if it’s messy. The AAP recommends children drink from an open cup by about age 2.
A few practical tips: choose a cup with two handles so small hands can grip it, fill it only with plain water between meals, and let your child practice during mealtimes when spills are easier to manage. Offering water in a cup rather than a bottle also helps with the bottle-to-cup transition, which ideally wraps up between 12 and 18 months.
Signs Your Child Needs More Water
Toddlers aren’t great at communicating thirst. Instead of waiting for your child to ask, offer water regularly, especially during and after meals. A simple way to check hydration: your child’s urine should be light, roughly the color of lemonade. If it looks dark, closer to apple juice, they need more fluids.
Watch for signs of dehydration, which include fewer wet diapers than usual, sunken eyes, few or no tears when crying, unusual drowsiness or irritability, and a soft spot on the head that appears sunken. These signs call for prompt attention, particularly during illness or hot weather.
Hot Weather and Illness
When it’s hot outside or your child has a fever, vomiting, or diarrhea, fluid needs increase. There’s no single formula for how much extra to offer. The best approach is to provide frequent small sips of water throughout the day, even before your child seems thirsty. Continue offering breast milk or formula if your child is still nursing, since these provide both fluids and electrolytes.
During outdoor play in warm weather, bring water along and offer it every 15 to 20 minutes. Children overheat faster than adults, and they rarely self-regulate their fluid intake well enough to keep up with what they’re losing through sweat.
Can a Toddler Drink Too Much Water?
It’s rare, but possible. Water intoxication happens when a child drinks so much plain water that sodium levels in the blood drop dangerously low. Symptoms include unusual irritability or sleepiness, swelling, low body temperature, and in severe cases, seizures. The risk is highest in babies under 6 months, whose kidneys are still immature, but it can happen in older infants and toddlers if water replaces milk or formula in large quantities.
At 12 months, sticking to the recommended range of a few ounces of water per day alongside appropriate milk intake keeps this risk essentially zero. The concern is less about a child grabbing extra sips and more about situations where water is used as a substitute for milk or formula throughout the day.