Water Intake Calculator
Estimate how much water you need each day from your weight, exercise, and climate.
NutritionScience-backed formula
Enter your details
Fill in the fields, then calculate
Enter your weight.
Enter exercise minutes.
Awaiting Data
Enter your details and tap Calculate to see your results appear here.
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ResultYour result appears here.
Why Hydration Matters
Water carries nutrients, controls temperature, and keeps joints moving. Even mild dehydration drains focus and energy.
Food and goals turn into simple daily targets you can hit.
Needs rise with body size, exercise, and heat. This tool adds all three for a personal target.
Food and other drinks count too, so treat the number as total fluid.
How to Use This Calculator
- Enter your weight.
- Add daily exercise minutes.
- Pick your climate.
- Tap Calculate for litres, ounces, and cups.
The Formula Used
Base = weight(kg) × 33 ml
Exercise = (minutes / 30) × 350 ml
Climate adds up to 700 ml
Exercise = (minutes / 30) × 350 ml
Climate adds up to 700 ml
- weight
- Body weight in kilograms.
- minutes
- Daily exercise time.
Understanding Your Results
Lower need
Under 2 L/day
Smaller body, light activity.
Typical
2 to 3 L/day
A common daily total.
Higher need
Above 3 L/day
Hot climate or hard training.
Listen to thirst
Pale-yellow urine
A simple sign you are well hydrated.
Tips to Improve
- Sip steadily rather than gulping late in the day.
- Drink more around workouts and in heat.
- Watch urine colour as a quick gauge.
- Eat water-rich fruit and vegetables.
Frequently Asked Questions
It is a rough guide, not science. Real needs scale with size, activity, and climate.
Rarely, but extreme intake can dilute sodium dangerously. Spread water through the day.
Yes. They hydrate despite a mild diuretic effect.
Scientific References
- Institute of Medicine. (2005). Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate. National Academies Press.
- Sawka, M. N., et al. (2007). ACSM position stand: Exercise and fluid replacement. Medicine & Science in Sports & Exercise, 39(2), 377–390.
- Popkin, B. M., et al. (2010). Water, hydration, and health. Nutrition Reviews, 68(8), 439–458.