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Key Features
Instant Calculation
Get accurate results in real time with our optimized algorithm.
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Daily water needs vary by body size, activity level, climate, and health — there's no single number that's right for everyone. This calculator gives a practical starting estimate using a widely-cited general guideline of about 33ml of water per kilogram of body weight, with an adjustment for exercise.
This is a general wellness guideline, not medical advice — consult a healthcare provider for guidance specific to any medical condition.
How it works
Enter your body weight and, optionally, your daily exercise minutes. The tool multiplies your weight by 33ml, then adds roughly 12ml per minute of exercise to account for extra fluid loss.
- Enter weight (kg).
- Enter daily exercise (minutes, optional).
- Click Calculate to see your results.
Examples
Baseline water intake for a 70kg adult
A 70kg adult with no exercise gets a baseline recommendation of about 2.31 liters (roughly 9.75 cups) per day.
Who should use it
- Getting a practical daily hydration target.
- Adjusting fluid intake around workout days.
Industry applications
- Fitness and personal training
- General wellness and nutrition
Advantages
- Quick, simple estimate requiring only body weight.
- Accounts for extra fluid needs from exercise.
Limitations
- Doesn't account for climate, altitude, pregnancy, or medical conditions.
- General guideline only, not personalized medical advice.
Common mistakes to avoid
- Treating the estimate as a strict medical requirement rather than a general starting guideline.
- Not adjusting upward for hot weather, altitude, or illness.
Best practices
- Use thirst and urine color as everyday practical indicators alongside this baseline estimate.
Tips
- Spread intake throughout the day rather than drinking it all at once, which your body absorbs and uses more effectively.