Water Intake Calculator
Find out how much water you should drink daily based on your weight and activity level.
kg
Daily Water Recommendation
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L
per day
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250 ml glasses / day
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500 ml bottles / day
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About the Water Intake Calculator
Proper hydration is essential for kidney function, temperature regulation, joint lubrication, and nutrient transport. The most common evidence-based recommendation is 35 ml of water per kilogram of body weight per day, adjusted for activity and climate.
Factors that increase your water needs
- Physical exercise and sports
- Hot or humid weather
- High-altitude environments
- Illness involving fever, vomiting, or diarrhoea
- Breastfeeding (add approximately 700 ml/day)
Frequently Asked Questions
How much water should I drink per day?
A common rule is 35 ml per kg of body weight. Active individuals and those in hot climates need more. The classic 8 glasses a day is a rough guideline that doesn't account for body size or activity.
Does coffee count as water intake?
Yes, caffeinated drinks like coffee and tea do contribute to daily fluid intake, contrary to the common myth that caffeine dehydrates. However, water and non-caffeinated drinks are preferable for optimal hydration.
What are signs of dehydration?
Early signs include dark yellow urine, dry mouth, fatigue, and headaches. Severe dehydration can cause dizziness, rapid heartbeat, and confusion. Urine should be pale yellow when well hydrated.
Should I drink more water when exercising?
Yes. Add 500–750 ml (17–25 oz) for every hour of moderate exercise. In hot weather or during intense exercise, you may need even more to replace sweat losses.