worldofcalcsWater Intake Calculator
Daily Water Intake
2670 mL
≈ 11 glasses (250ml each)
How much water do you need?
Your body loses water all day through breathing, sweat and urine, and needs it back to regulate temperature, digest food and keep your blood volume steady. How much you need depends mainly on your weight, how active you are and the climate. In hot Indian summers, and when you exercise, needs rise well above the usual '8 glasses' rule.
How the estimate is worked out
Daily water = 33 ml × weight (kg) + 12 ml × minutes of exercise
About 33 ml per kg of body weight covers a typical day, and about 12 ml per minute of exercise (roughly 350 ml per half hour) replaces sweat. This includes water from all drinks; food such as fruit, dal and curd also provides some. Drink more in hot or humid weather, at high altitude, during fever or diarrhoea, and when pregnant or breastfeeding.
Staying hydrated
- Pale yellow urine is a simple sign you're drinking enough; dark yellow means drink more.
- Thirst lags behind need, especially in older adults; drink regularly through the day rather than waiting.
- Tea and coffee count towards your intake; their mild diuretic effect is small in regular drinkers.
- In heat or heavy sweating, water alone may not be enough: ORS, nimbu pani with a pinch of salt or buttermilk replace lost salts.
- More isn't always better. Drinking several litres very quickly can be dangerous; spread it out.
- People with kidney or heart conditions may need to limit fluids; follow your doctor's advice.
Worked example
- Weight 70 kg, with 30 minutes of exercise a day
- Base need: 70 × 33 ml = 2,310 ml
- Exercise: 30 × 12 ml = 360 ml
- Total: about 2,670 ml a day, around 11 glasses of 250 ml
Daily water by weight and exercise
In millilitres; 1,000 ml is 1 litre.
| Weight | No exercise | 30 min exercise | 60 min exercise |
|---|---|---|---|
| 50 kg | 1,650 ml | 2,010 ml | 2,370 ml |
| 60 kg | 1,980 ml | 2,340 ml | 2,700 ml |
| 70 kg | 2,310 ml | 2,670 ml | 3,030 ml |
| 80 kg | 2,640 ml | 3,000 ml | 3,360 ml |
| 90 kg | 2,970 ml | 3,330 ml | 3,690 ml |
Add more in hot weather.