How Much Water Should I Drink Daily?

Medically Reviewed by Kathleen M. Zelman, RD, LD, MPH on November 13, 2022
4 min read

About 60% of your body weight is made of water. You need it for every single body function. It flushes toxins from your organs, carries nutrients to your cells, cushions your joints, and helps you digest the food you eat.

If you don’t get enough water, you can become dehydrated. Severe cases of dehydration can cause dizziness, confusion, and even seizures.

That’s why it’s important to get the water as your body needs every day. No set amount is right for everyone. How much you need can depend on your size, how much exercise you do, how hot the weather is, and other things. Your doctor can help you determine what’s right for you.

We’ve all heard that 8 glasses of water each day is best. But the truth is, how much water you need varies. But there are some basic guidelines:

  • For men, the Institute of Medicine (IOM) recommends a total of 13 cups (about 3 liters) of fluid each day.
  • For women, they suggest 9 cups (a little over 2 liters) of fluid each day. Pregnant women should drink about 10 cups of water daily. Those who breastfeed need about 12 cups.

If you’re outside on a hot day, or doing something that makes you sweat a lot, you’ll need to drink more fluids to stay hydrated. The same is true if you have an illness that causes you to throw up, have diarrhea, or run a fever.

If you have a condition like heart failure or a particular type of kidney disease, you may need to limit your fluid intake. Talk to your doctor about what’s right for you.

Like adults, how much water children need depends on many things, like their age, how much they weigh, and their gender. Other things that play a role include how healthy and active they are, and what the climate is like where they live.

In general, children and teens need about 6 to 8 cups of water a day. They should also eat lots of fresh fruits and veggies, which are full of water.

During play or exercise, a good goal is to drink a half cup to 2 cups of water every 15 to 20 minutes.

Water helps to keep you healthy in a number of ways. When you drink enough, it:

  • Helps you remove waste from your body through your urine, stool, and sweat
  • Helps your body stay a normal temperature, rather than overheating
  • Helps protect delicate tissues in your body
  • Keeps your joints cushioned and lubricated
  • Adds to skin health and keeping your skin plumped


Your recommended water intake includes all sources -- drinking water, other beverages, and food. But be careful -- certain fluids have their drawbacks.

For instance, juices, sodas, and smoothies can be hydrating, but they can also be high in sugar and calories.

Coffee and tea provide water, too. But, they also contain caffeine, which may have a mild diuretic effect. Most healthy people can safely drink about 2 to 4 8-ounce cups of coffee each day. Scale back if it makes you feel anxious or jittery.

Alcoholic drinks contain water, too. But like caffeine, they actually cause you to lose more water through your urine. This can lead to dehydration.

Sports drinks have a high water content. They also contain carbohydrates and electrolytes, which can help you absorb water and keep your energy levels up. During intense workouts, they help to replace salt lost through sweat. But be careful: many also contain lots of extra calories, sugar, and salt. Check the nutrition label. Pay attention to the serving size, and limit how many you drink.

Energy drinks are different from sports drinks. They contain sugar, as well as stimulants, like caffeine -- often in high doses. Many doctors recommend that children and teens avoid them.

And don’t forget foods! Fruits and vegetables like cucumbers, iceberg lettuce, celery, and watermelon are over 90% water. They also provide a variety of different vitamins and minerals. Refreshing! Soups, stews, gelatin, and more also contain fluids to meet your needs.

It’s rare if you’re a healthy adult who eats a regular American diet. But it can happen.

If you drink a lot of water but your kidneys can’t get rid of the excess, you could develop a condition doctors call “hyponatremia.” That means the minerals in your blood are diluted, or watered down. As a result, sodium levels in the blood fall. Your body’s water levels rise and your cells swell. It can lead to serious (even life-threatening) problems. Endurance athletes, like marathon runners, are at risk for this condition.

Certain health conditions can also play a role in how much water you need. Ask your doctor for guidance if you:


Do you drink enough fluid that you rarely feel thirsty? Is your pee either clear or light yellow? If you can answer “yes” to both, you’re probably getting all the fluid you need.

Show Sources


Harvard Medical School: “How Much Water Should You Drink?

Gov.UK: “Dehydration -- Symptoms.”

Mayo Clinic: “Nutrition and Healthy Eating.”

Academy of Nutrition and Dietetics: “Water: How Much Do Kids Need?”

British Nutrition Foundation: “Healthy Hydration Guide.”

American Academy of Family Physicians: “Hydration: Why It’s So Important.”

Physicians Committee for Responsible Medicine: “Hydrating Through Fruits and Veggies.”

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