Water Calculator
Optimal hydration based on your weight and activity.
How does the water intake calculator work?
The calculator estimates your daily water requirement based on three factors: body weight, physical activity level, and climate. The base recommendation is 30–35 ml of water per kilogram of body weight. Activity adds 0.3–0.6 liters extra, and hot or humid climates add another 0.5–1.0 liters. Enter your weight, choose your activity level and climate, and click "Calculate" to see your personalized daily hydration goal.
How to use the Water Calculator
Enter your weight in kilograms, select your typical weekly activity level, and choose your climate type. Click "Calculate" to instantly see the recommended total daily water intake in liters. This includes water from all sources — drinks and food — but most people get about 20% from food, so aim to drink the remainder as pure water.
Example calculation
A 70 kg person with moderate activity in a normal climate: Base = 70 × 0.033 ≈ 2.3 L, Activity bonus = +0.4 L, Total ≈ 2.7 L/day. In a very hot climate, add another 1.0 L → Total ≈ 3.7 L/day. The calculator adjusts the recommendation based on all three factors.
Frequently Asked Questions
Does coffee and tea count toward water intake?
Yes, all beverages contribute to your daily fluid intake, including coffee, tea, milk, and juice. However, water is the healthiest choice for hydration without added calories or caffeine. The calculator's recommendation covers total fluid intake.
Can I drink too much water?
While rare, excessive water consumption can lead to hyponatremia (low blood sodium). Follow the calculated recommendation as a guideline, listen to your body's thirst signals, and adjust based on your individual needs and medical conditions.