Free water intake calculator
Hydration is the most underrated pillar of physical and cognitive performance. Just 2% dehydration reduces mental capacity by 20%. This calculator estimates your daily water needs based on your weight, activity level and environment.
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Try for freeWhy hydration is crucial
Water makes up 60% of your body weight and is involved in virtually every biological function: temperature regulation, nutrient transport, mental focus, digestion and muscle performance. Studies show that optimal hydration improves concentration by 14% and reduces fatigue by 20%.
How to use this calculator
- 1Enter your weight in kg or lbs
- 2Select your physical activity level
- 3Choose your climate type
- 4Discover your daily goal in liters and glasses
- 5Follow the recommended daily schedule
Hydration tips
- •Drink a large glass of water right after waking up to compensate for overnight dehydration
- •Keep a reusable bottle always visible
- •Drink before, during and after exercise
- •Water-rich fruits and vegetables (cucumber, watermelon) count
- •Reduce coffee and alcohol which are diuretics
Frequently asked questions
The general rule is 33ml per kg of body weight, adjusted for activity and climate. For a sedentary 70kg person in a temperate climate, that's about 2.3L.
Yes, about 20% of our water intake comes from food (fruits, vegetables, soups). This calculator gives the total need, food included.
Coffee has a mild diuretic effect, but the water it contains more than compensates. However, beyond 3-4 cups, it's recommended to add an extra glass of water per cup.
The best indicator is urine color: pale yellow = good hydration, dark yellow = dehydration. Thirst is a late signal.