How Much Water Do I Need to Drink a Day?

March 26, 2018

You probably know drinking water is important for your health. But just how much do you need to drink each day? Does the eight 8-ounce glasses a day “rule” still apply?

Since we all have different hydrating needs, the information and guidelines below will help you determine what amount is best for you.

Eight Glasses a Day?

While there have been different recommendations regarding the ideal amount of water that should be consumed daily, including the popular advice to drink eight 8-ounce glasses a day, there isn’t a “one size fits all” formula.

Most healthy people can stay hydrated by drinking water and other fluids whenever they feel thirsty. For some people, fewer than eight glasses a day will be enough, for others eight glasses is ideal and other individuals will need more.

Recommendations by Age

Daily water needs will be different for adults than for children. The current recommendation for people 19 years of age and older is around 3.7 liters for men and 2.7 liters for women. These recommendations are for your overall fluid intake per day, which includes anything you eat or drink that contains water, such as fruits and vegetables.

Out of this overall fluid intake amount, it’s suggested that men should consume about 13 cups from beverages and women about 9 cups from beverages.

For children, the daily water intake recommendations are broken down into three groups based on age, with the recommended amount increasing as children get older:

  • Ages 4-8: About 40 ounces (or 5 cups) a day
  • Ages 9-13: About 56-64 ounces (or 7-8 cups) a day
  • Ages 14-18: About 64-88 ounces (or 8-11 cups) a day

Other Factors Affecting Individual Water Needs

In addition to an individual’s age, daily water needs are based on other factors, including:

  • Health Status: When you’re sick with a fever, vomiting or diarrhea, your body loses a lot of fluids. It’s essential to avoid dehydration by drinking more water or following a doctor’s recommendations for staying hydrated.
  • Activity Level: If you exercise or do any activity that makes you sweat, you’ll need to drink extra water to replace the fluid loss.
  • Environment: Additional fluid intake is needed when the weather is hot or humid to avoid dehydration.
  • Pregnancy or breast-feeding: Women who are pregnant or breast-feeding need additional fluids to stay hydrated. It’s recommended that pregnant women of all ages should aim to get 80 ounces (or ten 8-ounce glasses) of water each day. Breastfeeding women may need to increase their total daily water intake to 104 ounces (or 13 glasses).

The easiest way to determine what amount is best for you is to begin with eight 8-ounce glasses as your starting point and then adjust that amount up or down based on the above factors.

It will take some trial and error in the beginning to identify what your specific water needs are. If you track your daily water intake – along with how you feel mentally and physically each day – over time, you’ll be able to find the ideal amount your body needs to function optimally.