The amount of water you need to drink daily depends on your weight and activity level. According to the institute of Medicine, the average adult male requires roughly 13 cups of liquid a day. Females need about nine cups daily. The old adage of “drink eight glasses of water a day” is a good start, but aim for more. Here’s how:
Drink a glass with each meal, in between meals, and before, during and after exercise. Food provides about 20 percent of your daily water needs, so reach for foods such as watermelon, which is 90 percent water.
Check out this hydration calculator to see how much liquid you should be drinking.