Daily Water Intake Calculator
Your water needs depend on your body weight, how active you are and how hot it is. This tool gives a simple daily target in litres and glasses.
These health tools are still being tested and are updated regularly to give you a better experience. Results are estimates for information only — please confirm important results with a doctor. Read the medical disclaimer
Daily Water Intake Calculator
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About the Daily Water Intake Calculator
Water keeps your body temperature steady, protects your kidneys and helps digestion. In Indian summers you may need much more than the usual “8 glasses”.
How to use the Daily Water Intake Calculator
- Enter your weight.
- Add your average daily exercise time and choose your usual weather.
- Tell us if you are pregnant or breastfeeding.
- Press Calculate for an estimated daily amount in litres and glasses.
Formula explained
Daily water (mL) ≈ body weight (kg) × 30 to 35 mL
Add about 500 mL for each hour of exercise and 500 mL–1 L in hot or humid weather. About 20% of water usually comes from food.
People with heart failure, kidney disease or a doctor-advised fluid limit should follow their doctor’s advice instead.
Worked example: Daily Water Intake
Ravi weighs 60 kg, walks 45 minutes a day and lives in a hot city: 60 × 35 = 2,100 mL + 375 mL for exercise + 500 mL for heat = about 3.0 litres a day, or 12 glasses of 250 mL (including water from tea, milk and food).
Important limitations
- An estimate — needs change day to day with sweat, diet and health.
- Not for people with heart failure, kidney disease or a doctor-advised fluid limit.
- Children need different amounts.
Frequently asked questions
How do I know if I am drinking enough water?
Pale yellow urine and rarely feeling thirsty are good signs. Dark yellow urine, headaches and tiredness can mean you need more.
Do tea, coffee and fruits count?
Yes. Most drinks and water-rich foods like fruits, curd and dal count towards your intake. Sugary drinks add calories, so plain water is best.
Can I drink too much water?
Yes. Drinking several litres very quickly, especially during long exercise without salt, can dilute blood sodium (hyponatraemia), which is dangerous. Spread water through the day and drink to thirst plus a little more in heat.
Should I drink more when I have a fever or diarrhoea?
Yes — fever, vomiting and diarrhoea all increase fluid losses. Oral rehydration solution (ORS) is better than plain water for diarrhoea. Seek care if you cannot keep fluids down or pass very little urine.
Sources
- EFSA Panel on Dietetic Products. Scientific opinion on dietary reference values for water. EFSA Journal 2010;8(3):1459.
- US National Academies. Dietary Reference Intakes for water, 2005.
Medical disclaimer: If you have heart, kidney or liver disease or have been told to limit fluids, follow your doctor’s advice rather than this estimate. These tools give general information and estimates only. They are not a diagnosis and do not replace advice from a qualified doctor. Always talk to your doctor about your results, and seek urgent medical help in an emergency. In an emergency call 112. Medical disclaimer · Terms of use · Privacy policy
