Water: How Much Do Kids Need?

Water is one of the body's most essential nutrients. People may survive a few weeks without any food, but they couldn't live more than a few days without water. That's because water is the cornerstone for all body functions. It's the most abundant substance in the body, averaging around 50% to 70% of body weight. It helps keep body temperature constant, and it transports nutrients and oxygen to all cells and carries waste products away. Water helps maintain blood volume, and it helps lubricate joints and body tissues such as those in the mouth, eyes and nose.

How Much Water Do Kids Need?

The daily amount of water that a child needs depends on factors such as age, weight and sex. Air temperature, humidity, activity level and a person's overall health affect daily water requirements, too. The chart below can help you estimate how many cups of water your child or teen needs each day. These recommendations are for generally healthy kids living in temperate climates; therefore, they might not be exact for your child or teen.

The amount of water that your child or teen needs each day is actually a little lower than the recommendations listed in the chart below. That’s because, in addition to drinking water, choices such as milk, fruits and vegetables have a much higher water content than other solid foods and contribute to daily fluid needs.

Kids Total Daily Water Requirements

Age Range Sex Cups/Day
4 to 8 years Girls and Boys 7
9 to 13 years Girls 9
Boys 10
14 to 18 years Girls 10
Boys 14

Data are from Institute of Medicine of the National Academies. Dietary Reference Intakes (DRIs) Tables. Recommended Daily Allowance and Adequate Intake Values: Total Water and Macronutrients.