Children, four to eight, require 1.3 litres (5.5 cups). Teenagers need to drink more – about 1.8 litres (seven cups) for girls and 2.6 litres (10.5 cups) for boys.

The data, from the U.S. National Health Nutrition Examination Survey for 2009 to 2012, found that adult men take in 117 ounces of water daily, on average — more than 14 cups. For women, the number is 93 ounces, or almost 12 cups daily.

Women of reproductive age

Girls and boys between 4 and 8 years old should drink 40 ounces per day, or 5 cups. This amount increases to 56–64 ounces, or 7–8 cups, by ages 9 to 13 years. For ages 14 to 18, the recommended water intake is 64–88 ounces, or 8–11 cups. One may also ask, how much water should you drink based on your weight?

According to the IOM, toddlers and 4- to 8-year-olds should get 4 to 5 cups of water a day—from drinking water and other sources—while 9- to 13-year olds should aim for 7 to 8 cups, and 14- to 18-year-olds should get 8 to 11 cups.

The Institute of Medicine says children and teenagers should consume about two to three quarts of water a day (1.7 to 3.3 liters, the IOM says), depending on age, size and sex. Adolescent boys generally need to drink more water than girls do, research suggests.

In general, children and teens need about 6 to 8 cups of water a day. They should also eat lots of fresh fruits and veggies, which are full of water. During play or exercise, a good goal is to drink a half cup to 2 cups of water every 15 to 20 minutes.

A new article published in the Harvard Health Letter recommends drinking 30 to 50 ounces a day, an amount equal to about four to six glasses of water.

But drinking more water should be only one small part of your wellness journey. “Drinking water is not going to have a huge weight loss effect, and without calorie restriction and/or exercise, just drinking water is not likely to lead to significant weight loss,” Jampolis says.