Water Intake Calculator
Water Intake Calculator
A daily hydration estimate based on body weight and exercise.
Estimate only, not medical advice. A rough estimate. Needs vary with climate, diet, health conditions and medications. Thirst and urine color are good everyday cues.
Free to use and save. A free account keeps your results in your private journal, and the ads on the calculator pages are hidden while you are signed in.
How this is calculated
There is no single official figure. This uses a common rule of thumb of about 30 to 35 mL of water per kg of body weight per day, plus roughly 350 mL for every 30 minutes of exercise. For reference, the U.S. National Academies adequate intake for total water, from drinks and food, is about 3.7 L a day for men and 2.7 L for women. Treat it as a starting point. If you choose Other / prefer not to say, the reference intake is the average of the male and female values. Everything is calculated in your browser, and nothing you enter is stored or sent anywhere.