About the Water Intake Calculator
How much water to drink per day based on body weight, activity, climate and other drinks.
Also known as: how much water should i drink, daily water intake, hydration calculator, water per body weight, hydration goal, fluid intake.
How to use this calculator
- Enter units, exercise per day, climate and the other fields.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
≈ 33 ml per kg of body weight + 350 ml per 30 min of exercise
Worked example
Using the values pre-filled in the calculator above:
- Units: Metric (kg, cm)
- Weight = 70 kg
- Exercise per day = 45 min
- Climate: Temperate
the calculator returns:
- Daily water: 2.84 litres
- Glasses (250 ml): 11
- US fluid ounces: 96 fl oz
- Bottles (500 ml): 5.7