Water Intake Calculator
Find your daily water target from weight and activity.
Frequently Asked Questions
How is daily water intake calculated?
A widely used guide is 35 ml per kilogram of body weight, plus about 350 ml for every 30 minutes of exercise, with extra in hot weather to replace sweat losses.
Does food count toward hydration?
Yes. Food typically provides 20 to 30 percent of daily water, especially fruit, vegetables and cooked grains. This calculator targets drinking water, so total hydration will be a little higher.
Can you drink too much water?
Yes, though it is uncommon. Forcing very large volumes in a short time can dilute blood sodium (hyponatremia). Spread intake through the day and drink to thirst around the target.
Is the Water Intake Calculator free, and is my data private?
Yes. It is completely free and every calculation runs locally in your browser, so the numbers and dates you enter are never uploaded, stored, or shared with anyone.
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