This water intake calculator gives a rough estimate of how much water you should drink in a day, based on your body weight, how much you exercise and whether you live in a hot, humid climate such as Bangladesh or much of India.
How the estimate is made
There is no single official formula for daily water needs. This calculator uses a common rule of thumb: about 35 ml per kg of body weight, plus about 350 ml for every 30 minutes of exercise, plus about 500 ml in hot or humid weather. Treat the result as a starting point, not a prescription.
Example
A person weighing 60 kg who exercises 30 minutes a day in a hot climate gets an estimate of about 3.0 litres (around 12 glasses).
Signs you may need more water
- Dark yellow urine or urinating less often than usual.
- Thirst, dry mouth, headache or tiredness.
- Heavy sweating in summer, during fever, or with diarrhoea or vomiting.
Frequently asked questions
Do tea, milk and food count?
Yes. Food (especially fruit, vegetables and rice with curry), milk, tea and other drinks all contribute to your fluid intake.
Can drinking too much water be harmful?
Yes, drinking very large amounts in a short time can be dangerous. People with kidney disease, heart failure or on fluid restriction should follow their doctor’s advice.
Disclaimer: this tool is for general information only and is not medical advice.