Calculate your daily water intake needs based on weight, activity level, and climate. Free water intake calculator with formula, examples, and FAQ.
Proper hydration is essential for every bodily function, including temperature regulation, joint lubrication, nutrient transport, and waste removal. The water intake calculator estimates your daily fluid needs based on your body weight, physical activity level, and the climate you live in. Individual needs may vary based on health conditions and medications.
Base Water = Weight(kg) × 33 ml
Activity Addition: Sedentary +0ml | Light +200ml | Moderate +400ml | Active +600ml | Very Active +800ml
Climate Addition: Cold -200ml | Temperate +0ml | Hot +400mlThe base calculation of 33ml per kg of body weight provides a starting point. Additional water is needed to replace fluids lost through exercise (sweat) and hot climates. In cold climates, the body may need slightly less due to reduced sweating, but heated indoor air can still cause dehydration.
| Input | Output |
|---|---|
| 70 kg, moderate activity, temperate climate | Water: 2.7 liters/day (2,710 ml) |
| 60 kg, active, hot climate | Water: 3.0 liters/day (2,980 ml) |
| 85 kg, sedentary, cold climate | Water: 2.6 liters/day (2,605 ml) |