How much water should you drink a day?
There is no single rule, but US health experts suggest about 3.7 liters of total water a day for men and 2.7 liters for women, from all drinks and food.
The figures come from the US National Academies of Sciences, Engineering, and Medicine. They include water from every source. About 20 percent of daily water usually comes from food, especially fruit and vegetables, and the rest from drinks, including tea, coffee and milk.
Needs vary with body size, activity, climate, health and pregnancy. People who exercise hard or live in hot places need more. For most healthy adults, drinking when thirsty and having pale yellow urine are good signs of enough water.
The 8 glasses rule
The popular advice to drink eight glasses of water a day is easy to remember but not based on strong science. Drinking far too much water in a short time can be dangerous, because it can lower the salt level in the blood.
Did You Know?
Older adults may feel less thirsty than younger people, so they can become dehydrated more easily and may need to drink regularly even without feeling thirsty.
This answer is general information, not medical advice. For a personal health question, talk to a doctor.