The amount of water a child needs each day depends on their age, size, and activity level. A toddler may need just 4 cups of total fluids, while a teenager might need 8 to 11 cups. Those numbers include water from all sources: plain water, milk, and even the water content in food, which accounts for roughly 30% of a young child’s daily intake.
Infants: Birth to 12 Months
Babies under 6 months old don’t need plain water at all. Breast milk or formula provides all the hydration they require. Even on hot days, the recommendation is to offer additional breast milk or formula rather than water.
Between 6 and 12 months, you can start introducing small sips of plain water as your baby begins eating solid foods. The CDC recommends 4 to 8 ounces per day in this window. That’s roughly half a cup to one cup, offered throughout the day in a sippy cup or open cup during meals. Keeping the amount modest matters: babies under a year can develop water intoxication because their small bodies don’t need much. If you feel your infant needs water outside of mealtimes, keep it under 3 ounces at a time.
Toddlers and Preschoolers: Ages 1 to 5
Once your child turns 1, water and milk become the two main beverages. For 12- to 24-month-olds, aim for about 2 cups (16 ounces) of whole milk per day alongside regular water. After age 2, you can switch to low-fat or skim milk, and kids ages 2 to 5 can have 2 to 3 cups of milk daily.
Juice is fine in small amounts but shouldn’t replace water. For 2- to 3-year-olds, the limit is 4 ounces of 100% juice per day. For 4- to 5-year-olds, it’s 4 to 6 ounces. That’s less than a standard juice box in many cases. The rest of their fluid intake should come from plain water. In total, most toddlers need about 4 cups of fluid daily, and preschoolers need around 5 cups, with plain water filling the gap after milk and any juice.
School-Age Kids: Ages 6 to 13
As children grow, their fluid needs climb. Girls ages 9 to 13 generally need about 7 cups of total beverages per day, while boys the same age need closer to 8 cups. For younger school-age kids (6 to 8), around 5 to 6 cups is a reasonable target. These numbers refer to all beverages combined, so water, milk, and other drinks all count.
A practical approach is to send your child to school with a reusable water bottle and encourage drinking at every meal and snack. Many kids simply forget to drink unless water is visible and accessible. If your child’s school allows water bottles in the classroom, filling one each morning creates a built-in reminder.
Teenagers: Ages 14 to 18
Teen girls need roughly 8 cups of beverages daily, and teen boys need about 11 cups. These are averages for moderate activity in a temperate climate. Teens who play sports, live in warm regions, or spend time outdoors in summer will need more.
Teenagers are also more likely to reach for sugary drinks, energy drinks, or coffee. Plain water and milk remain the best choices. Sports drinks are rarely necessary, even for active teens (more on that below).
Extra Water for Active Kids
Physical activity changes the math significantly. The American Academy of Pediatrics recommends that school-age children and adolescents drink 4 to 8 ounces of water every 15 to 20 minutes during exercise. That adds up fast: a child at a 90-minute soccer practice could need an extra 18 to 36 ounces on top of their normal daily intake.
Before practice or a game, your child should drink water or milk at least an hour or two beforehand, ideally paired with a salty snack to maintain electrolyte balance. Afterward, a carbohydrate-rich snack within 30 minutes helps with recovery, followed by another snack about two hours later. Sports drinks aren’t necessary for most kids. Water and regular food do the job.
If you want a precise read on whether your child is drinking enough during activity, weigh them (without clothes) before and after exercise. Their weight should stay roughly the same. Every pound lost equals about 16 ounces of fluid that needs replacing.
Hot Weather and Humidity
Heat increases fluid loss through sweat, even when kids aren’t exercising. On hot days, offer water proactively rather than waiting for your child to say they’re thirsty. Thirst is a lagging signal, especially in young children who may not recognize it or articulate it.
Keep water bottles within reach at all times. If you’re heading outside, bring water along even for short outings. Schedule regular breaks indoors to cool off and drink. There’s no single formula for how much extra fluid hot weather demands because it varies with temperature, humidity, and the child’s activity level, but the goal is steady, frequent sips throughout the day rather than large volumes at once.
How to Tell If Your Child Is Hydrated
The simplest check is urine color. Pale yellow is ideal and means your child is well-hydrated. Dark yellow suggests mild dehydration, meaning they need to drink more. Amber or honey-colored urine signals clear dehydration. On the other end, completely clear urine usually just means they’ve been drinking a lot of water recently.
Other signs of dehydration to watch for include dry lips and mouth, fewer trips to the bathroom than usual, tiredness, irritability, and headaches. Young children may cry without producing tears or seem unusually sleepy. If your child’s urine stays dark despite drinking more fluids, or if they show multiple signs of dehydration, that warrants attention.
Can Kids Drink Too Much Water?
It’s rare, but yes. Water intoxication happens when someone drinks so much water that it dilutes the sodium in their blood to dangerous levels. Symptoms start with nausea, bloating, and headache, then can progress to confusion, muscle weakness, and in severe cases, seizures.
Infants are most vulnerable because of their small size. For older children and teens, the general guideline is to avoid drinking more than about 32 ounces (a liter) in a single hour. This is most relevant during sports, where well-meaning kids or coaches might push excessive water intake. Steady sipping throughout the day is always safer than gulping large quantities at once.
Choosing the Right Beverages
Water and plain milk should make up the vast majority of what your child drinks. Here’s how other common beverages stack up:
- 100% fruit juice: Limit to 4 ounces per day for kids under 4, and 4 to 6 ounces for ages 4 to 5. Older kids can have up to 8 ounces. Skip juice entirely for babies under 1.
- Flavored milk and plant milks: Flavored milks add sugar. Unsweetened plant milks can work but vary widely in protein and nutrient content.
- Sports drinks: Unnecessary for most children, even after hard exercise. A snack and water cover the same ground without the added sugar.
- Soda, sweet tea, and energy drinks: These provide no hydration benefit over water and add significant sugar or caffeine. They’re best avoided entirely for young children.
If your child resists plain water, try adding slices of fruit like strawberries, cucumber, or citrus. Serving water cold and in a cup or bottle your child likes can also make a difference. Building the water habit early means less battling over beverages later.