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How Much Water Should I Drink a Day?

Estimate how much water to drink each day based on your weight, exercise, and climate. See the answer in ounces, cups, and liters.

How to use the Water Intake Calculator

  1. Enter your weight in pounds.
  2. Enter how many minutes you exercise each day.
  3. Check the box if it is hot where you live, then read your daily goal.

Water intake by weight

Weight Daily water (no exercise)
120 lb 60 oz (7.5 cups)
150 lb 75 oz (about 9.5 cups)
180 lb 90 oz (about 11 cups)
210 lb 105 oz (about 13 cups)

Easy ways to drink more water

  • Keep a refillable bottle with you.
  • Drink a glass with every meal.
  • Add lemon or fruit for flavor.
  • Eat water-rich foods like watermelon, cucumbers, and oranges.

If your tap water tastes off, see why tap water tastes like chlorine. This tool gives a general estimate and is not medical advice.

Frequently asked questions

How much water should I drink a day?

A common rule of thumb is half your body weight in ounces, plus more when you exercise or it is hot. The National Academies suggest about 15.5 cups of total fluids a day for men and 11.5 cups for women, including water from food and other drinks.

Do coffee, tea, and food count?

Yes. All drinks count toward your fluids, and about 20 percent of daily water usually comes from food like fruits, vegetables, and soup.

How do I know if I am drinking enough?

Pale yellow urine and rarely feeling thirsty are good signs. Dark urine, headaches, and tiredness can mean you need more water.

Learn more