How much water are you supposed to drink a day?

According to Mayo Clinic, men should drink about 13 cups, or 13 8-ounce glasses of fluids daily, while women should drink 9 cups. The clinic points out that all fluids, not just water, count toward the total.

WebMD says that eight 8-ounce glasses of water per day are usually enough, but the number varies depending on the amount of heat and humidity in the environment, the person's exercise intensity and any illnesses or pregnancies that are present. People can receive water through foods, such as watermelon. Urine that is transparent or pale yellow shows someone is drinking enough water, while dark-yellow urine indicates a need for increased water consumption.