Your body is about 60 percent water.
The body constantly loses water throughout the day, mostly through urine and sweat but also from regular body functions like breathing. To prevent dehydration, you need to get plenty of water from drink and food every day.
There are many different opinions on just how much water you should be drinking every day.
Health experts commonly recommend eight 8-ounce glasses, which equals about 2 liters, or half a gallon a day. This is called the 8×8 rule and is very easy to remember.
However, some experts believe that you need to sip on water constantly throughout the day, even when you’re not thirsty.
As with most things, this depends on the individual. Many factors (both internal and external) ultimately affect how much water you need.
This article takes a look at some water intake studies to separate fact from fiction and explains how to easily stay well hydrated for your individual needs.
How much water do you need?
How much water you need depends on a lot of things and varies from person to person. For adults, the general recommendation from The U.S. National Academies of Sciences, Engineering, and Medicine is about:
- 11.5 cups (2.7 liters) a day for women
- 15.5 cups (3.7 liters) a day for men
You might need more water than someone else. How much water you need also depends on:
- Where you live. You will need more water in hot, humid, or dry areas. You’ll also need more water if you live in the mountains or at a high altitude (3Trusted Source).
- Your diet. If you drink a lot of coffee and other caffeinated beverages you might lose more water through extra urination. You will likely also need to drink more water if your diet is high in salty, spicy, or sugary foods. Or, more water is necessary if you don’t eat a lot of hydrating foods that are high in water like fresh or cooked fruits and vegetables.
- The temperature or season. You may need more water in warmer months than cooler ones due to perspiration.
- Your environment. If you spend more time outdoors in the sun or hot temperatures or in a heated room, you might feel thirstier faster.
- How active you are. If you are active during the day or walk or stand a lot, you’ll need more water than someone who’s sitting at a desk. If you exercise or do any intense activity, you will need to drink more to cover water loss.
- Your health. If you have an infection or a fever, or if you lose fluids through vomiting or diarrhea, you will need to drink more water. If you have a health condition like diabetes you will also need more water. Some medications like diuretics can also make you lose water.
- Pregnant or breastfeeding. If you’re pregnant or nursing your baby, you’ll need to drink extra water to stay hydrated. Your body is doing the work for two (or more), after all.