How Much Water is in the Human Body

by Jay | Updated on July 26th, 2022

You need several things in life to survive. Water is one of the essentials you need to live a healthy life and survive. It serves various essential functions to keep you going.  


According to Dr. Jeffrey Utz, Neuroscience, pediatrics, Allegheny University, different people have varying percentages of their bodies made up of water. With babies having the most percentage.

man in white crew neck t-shirt drinking from black sports bottle

Newborns are born at around 78%. This drops to around 65% by one year of age. In adult men, around 60% of their bodies are water.

On the other hand, adult women have approximately 55% of their bodies made of water. This is because women tend to have more fat tissue, which doesn’t have much water as lean tissues. Therefore:

  • Kids and babies have more water than adults.
  • Women have less water than men.
  • Individuals with more fatty tissue have less water than people with less fatty tissue.

Further, according to H.H. Mitchell, Journal of Biological Chemistry 158, the lungs are composed of 83% water and the heart and brain around 73% water. In addition, bones contain 31% water, skin is about 64% water, and muscles and kidneys are 79%.

As you can see, water is vital for essential functions to keep going. Its unique properties are what make it so vital and basic to life. For example, water has an excellent ability to dissolve many substances.

And considering cells in our bodies are full of water, they can use valuable minerals, chemicals, and nutrients in biological processes. Furthermore, water is key in transporting protein and carbohydrates in the bloodstream. It also:

  • Transports waste material out of your body
  • Regulate your internal body temperature by respiration and sweating
  • Acts as a shock absorber for the fetus, spinal cord, and brain
  • Forms saliva
  • A crucial nutrient to the life of every cell (acts first as a building material)
  • Lubricate joints 
  • Needed by the brain to create hormones and neurotransmitters
  • Keeps mucosal membranes moist
  • Allows body’s cells to grow, reproduce and survive
  • Flushes body waste mainly through urine
  • Converts and digests food to components needed for survival
  • Helps deliver oxygen throughout the body
  • Water is the major component of most body parts

What amount of water should you consume to survive?

woman in black long sleeve shirt holding blue plastic bottle

Every person should drink a certain amount of water to survive. This amount can vary according to age, gender, physical activity, weight, health, and where you live. An adult female needs about 2.2 liters per day, while an adult male needs around 3 liters per day. See the guide below for more info:

AgeRecommended fluid intake (milliliters per day)
0–6 months700
6–12 months800
1–2 years1,300
4–8 years1,700
9–13 years (males)2,400
9–13 years (females)2,100
14–18 years (males)3,300
14–18 years (females)2,300
Adult male3,700
Adult female2,700
During pregnancy3,000
While breastfeeding3,800

Bonus! All the water you need doesn’t have to come from drinking liquids, as some of this water is present in the food you eat.

How to maintain a healthy percentage

man face with water droplets

Drinking enough fluids and eating the required amount of food throughout the day is one way to ensure your body has enough water to support vital functions. However, it would help if yIn addition, you considered taking more water after exercise or in hot weather.

The Centers for Disease Control and Prevention (CDC) also recommend:

  • Selecting water instead of sugar-sweetened drinks
  • Carrying a water bottle for easy access
  • Adding a wedge of lime or lemon to the water to enhance the taste
  • Taking water when eating a meal out

Tips for older adults

  • Not waiting until feeling thirst to drink liquids
  • Taking a sip of water between each bite of food at meals
  • Sipping a glass of water before and after exercise
  • Taking a full glass of water when taking medication

How to avoid dehydration

  • Drink enough water in a warmer or hot climate
  • Drink at least a glass before and after physical exercise
  • Drink fluid throughout the day. This is crucial for older adults as they gradually lose their sense of thirst. If they wait to feel thirsty, it is highly likely they may already be slightly dehydrated by that time. 

How much water is too much?

While drinking too much water is difficult, it is good to avoid overdoing it as it can lead to water toxicity (when you have too much water in the body).

Water toxicity results in the dilution of essential electrolytes in the blood, causing the cell to swell and pressure the brain.   

 You will also burden your kidneys when you drink too much water. Although, essentially, they can remove 20 – 28 liters of water per day. Nevertheless, they cannot excrete more than 0.8 – 1.0 liters per hour.

How do you determine your water percentage?

woman in white long sleeve shirt and black pants sitting on white chair

You can use the Watson Formula or online calculators to determine the percentage of water in your body. 

Watson’s formula for women

–2.097 + (0.1069 x height in centimeters) + (0.2466 x weight in kilograms) = total body weight (TBW) in liters.

Watson’s formula for men

2.447 – (0.09145 x age) + (0.1074 x height in centimeters) + (0.3362 x weight in kilograms) = total body weight (TBW) in liters.

Note! To get the percentage of water in your body, assume 1 liter equals 1 kilogram and then divide your TBW by weight. It is a basic estimate, but it will give you a rough idea if you are in a healthy range for the percentage of water in your body.

In conclusion

Our bodies need water to survive and support core functions. Therefore, ensuring you drink enough water daily is crucial in maintaining a healthy balance. But remember, how much water you need is determined by many factors. So, don’t compete with anyone. 

Jay

Jay is a health and wellness enthusiast with expertise in water quality and nutrition. As a knowledgeable advocate for holistic well-being, Jay successfully manages Type 2 Diabetes through informed lifestyle choices. Committed to sharing reliable and authoritative insights, Jay combines firsthand experience with a passion for enhancing health."