How much water should a child drink?
A simple by-weight estimate to start with — and the everyday signals that matter more than any number.
Kids don't need a complicated hydration plan. A weight-based estimate gives you a sensible daily target, and then their thirst and energy fill in the rest.
The short answer: this calculator uses the Holliday-Segar maintenance method to turn your child's weight into a daily fluid amount. Move it up on hot days and when they're active, and remember that food counts too.
Estimate your child's daily fluid
Children's Water Intake
A simple daily fluid estimate for kids, by weight.
Think of the number as a friendly starting point, not a strict quota. Active play, sports, and hot weather all raise the amount a child needs, sometimes by a lot.
The simplest everyday check is still the best one: a child who isn't thirsty and has pale, straw-colored urine is generally well hydrated.
Common questions
How much water should a child drink a day?
A common starting estimate uses the child’s weight: this calculator applies the Holliday-Segar maintenance method to give a daily fluid amount in cups, liters, and ounces. It’s a starting point — children need more when they’re active or in the heat.
Does food count toward a child’s fluid?
Yes. The estimate covers total daily fluid from drinks and food, and water-rich foods like fruit, vegetables, soup, and yogurt all contribute. Plain water is still the best everyday default for drinks.
How can I tell if my child is drinking enough?
Day to day, thirst and pale-yellow urine are good signals. Dark urine, dry mouth, or unusual tiredness can mean they need more — and needs rise with activity, hot weather, and illness.
This is general education, not medical advice. Some conditions change a child's fluid needs — check with your pediatrician if that applies.