Multimedia Gallery

How Many Cups of Water?

The human body's principal component is water, making up to 70% of your body weight according to the Mayo Clinic. The old adage says that we should be drinking 8 glasses of water a day, but is that number accurate? We'll explore in the U.S. National Science Foundation's "Discovery Files."

Water is essential to keeping your body working properly, but there is no universally applicable guideline for exactly how much water people should drink.

Supported in part by NSF, researchers at Duke and the University of Wisconsin-Madison have recently published the results of a study made by more than 90 partners measuring the water turnover of more than 5600 people. The subjects came from 26 countries, with ages raging from 8 days to 96 years old and were found to average between 1 and 6 liters of water turnover a day. The old 8 glasses adage would equate to approximately 2 liters, so not wholly wrong, but not universally accurate either.

Many factors impact these figures from age and sex to physical activity and environmental factors.

The study aimed to establish guidelines for public health officials to be able to anticipate daily intake demands as we respond to crises.

These guidelines are of increasing importance as the global population continues to grow and climate change impacts the availability of consumable water.

To hear more science and engineering news, including the researchers making it, subscribe to "NSF's Discovery Files" podcast.

Images and other media in the National Science Foundation Multimedia Gallery are available for use in print and electronic material by NSF employees, members of the media, university staff, teachers and the general public. All media in the gallery are intended for personal, educational and nonprofit/non-commercial use only.

Images credited to the National Science Foundation, a federal agency, are in the public domain. The images were created by employees of the United States Government as part of their official duties or prepared by contractors as "works for hire" for NSF. You may freely use NSF-credited images and, at your discretion, credit NSF with a "Courtesy: National Science Foundation" notation.

Additional information about general usage can be found in Conditions.