Water Intake Calculator

A daily hydration target from your weight and activity.

Quick answer: Calculate your ideal water intake online. Free hydration calculator using your weight and activity levels to recommend daily water amounts.

min
Daily water target2.8 liters
In US cups11.8 cups
In fluid ounces95 fl oz
NoteA general estimate; needs vary with climate, health, and diet.

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Estimate how much water to drink per day based on your body weight and exercise time, shown in liters, cups, and fluid ounces.

How it works

  1. Enter your body weight.
  2. Enter your typical daily exercise time in minutes.
  3. Review your recommended hydration target in liters, cups, and ounces.

Frequently asked questions

Is the 8-glasses rule real?

It is a rough rule of thumb. Actual needs scale with body size and activity, which is what this tool estimates.

Does coffee or tea count?

Mostly yes; the mild diuretic effect of caffeine is outweighed by the fluid. Water remains the best choice.

Can I drink too much?

Rarely, but overhydration (hyponatremia) is possible with extreme intake. Let thirst and urine color guide you alongside this estimate.

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