Health Calculators
Water Intake Calculator
Find out how much water you should drink daily based on your weight and how active you are.
About the Water Intake Calculator
Staying hydrated supports energy, focus and overall health. This water intake calculator estimates a sensible daily target based on your body weight, then adds extra for exercise.
The result is shown in litres, millilitres and glasses so you can track it however you prefer.
How to use the Water Intake Calculator
- Enter your weight in kilograms.
- Enter your daily exercise in minutes.
- Click Calculate Water Intake.
How the calculation works
Water (ml) ≈ weight (kg) × 33 + 350 ml per 30 min of exercise
Example
A 70 kg person who exercises 30 minutes a day should aim for about 2.66 litres, or roughly 11 glasses.
Frequently asked questions
A common guide is around 30–35 ml per kilogram of body weight, plus more when you exercise or the weather is hot.
Yes, water in tea, coffee, milk and food contributes, though plain water is the best primary source.
Very high intakes over a short time can be harmful. This calculator suggests a normal daily range, not a limit to exceed.
It offers a general estimate. Individual needs vary with health conditions, climate and activity, so use it as a guide.