How much water do you really need in a day?
Eight glasses is a fine habit, but it is not the official number. The real guidance is more flexible, and kinder.
Most of us grew up hearing that we should drink eight glasses of water a day. It is easy to remember, but it is not what the science panels actually say.
The numbers
The National Academies of Sciences, Engineering, and Medicine looked at how much water healthy, well-hydrated adults take in. The averages came out to about 2.7 liters a day for women (91 ounces) and about 3.7 liters a day for men (125 ounces).
The key word is total. Those figures count everything: plain water, other drinks, and the water in your food.
Food and other drinks count
Roughly 80 percent of our water comes from what we drink and about 20 percent from what we eat. Fruit, soup and vegetables all add to the total. So do coffee and tea. The panel counted caffeinated drinks too.
Let thirst do the math
The same report says that for most healthy people, drinking when you are thirsty and having something with meals is enough to stay hydrated day to day. You will need more when it is hot, when you are very active, or when you are sick.
Easy ways to drink a bit more
- Keep a bottle where you can see it.
- Have a glass of water with each meal.
- If plain water bores you, try sparkling water or unsweetened iced tea.
- Go easy on sugary drinks. They hydrate you, but the added sugar adds up fast.
This is general information to help you shop, not medical advice. If you have a health condition or take medication, ask your doctor or pharmacist what is right for you.