Water Intake Calculator
Based on your body weight, with a bump for exercise, this gives a rough daily water target in litres, millilitres and cups. Take it as a general guide rather than medical advice — and your inputs are never stored.
- 100% free
- Private & safe
- Runs in your browser
Why use Water Intake Calculator?
Water Intake Calculator gives a quick, private estimate using well-established formulas — informational only, and nothing you enter is stored.
- Runs instantly in your browser — nothing to install, nothing uploaded.
- Completely free, with no account, no watermarks and no usage limits.
- Handles Baseline ≈ 35 ml per kg of body weight; Plus ≈ 350 ml per 30 minutes of exercise.
- Choose metric or US units.
- Works on any device — desktop, tablet and phone — and is fully keyboard accessible.
How to use Water Intake Calculator
- Choose metric or US units.
- Enter your body weight.
- Add your typical daily exercise in minutes.
- See a suggested daily water target.
Examples
- A baseline target for a 70 kg adult.
- Adding water for a 45-minute workout.
Supported formats & limits
- Baseline ≈ 35 ml per kg of body weight
- Plus ≈ 350 ml per 30 minutes of exercise
Limitations
- A rough guideline only; real needs depend on climate, health, diet and pregnancy.
- Not medical advice — consult a professional for personalized guidance.
Frequently asked questions
Is this medical advice?
No — it is a general informational estimate. Individual hydration needs vary.
Does climate matter?
Yes — hot or humid conditions and altitude increase needs beyond this estimate.
Are my inputs stored?
No — everything is calculated locally in your browser.
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