Daily Water Intake Calculator
Free daily water intake calculator: estimate how much water you should drink based on body weight, exercise and weather, with a cup conversion for easy tracking.
How to Use
- Enter your weight
Type your weight in kilograms; the baseline is 30ml per kg.
- Pick exercise and environment
Choose your daily exercise duration and environment (cool, normal or hot) and the tool adds the extra fluid.
- Read the target
The results show your daily target in millilitres, the exercise top-up and the cup conversion (250ml per cup).
FAQ
How much water should I drink a day?
A common guideline is about 30ml per kilogram of body weight. A 65 kg person starts at about 1,950ml, plus more for exercise and heat.
How should I hydrate during exercise?
About one hour of moderate exercise needs roughly 600ml extra. Long, intense sessions also call for electrolytes — plain water alone can dilute sodium.
Can I drink too much water?
Healthy kidneys process roughly 800-1000ml per hour. Gulping 3-4 litres in a short time can cause hyponatremia. Drink in smaller amounts throughout the day.
How can I tell if I drink enough?
The easiest check is urine colour: pale yellow means hydrated, dark yellow means drink up, almost clear may mean a bit too much.