How much water should a teenager drink in a day?

Children should drink between 6-8 glasses a day.

The standard recommendation of water intake for children is at least 6-8 glasses (1.5 - 2 liters) a day, drunk regularly throughout the day (at least 3-4 glasses while at school) ensuring that plenty of additional fluid is drunk during warm weather and/or when exercising.

For teenage boys aged 14 over who require a higher average fluid intake of 2.6 liters (about 11 large glasses).

Adults should drink half of their body weight in ounces if they only exercise about 20 minutes a day, and it is not extremely hot weather. It might be the same for children. For example if a person weighs 130 pounds they should drink at least 65 ounces of water a day.