Water Intake Calculator

How Much Water Do You Need?

Your body uses water for almost everything: carrying nutrients, keeping you cool, and removing waste. You lose it all day through sweat, breath, and urine, so it needs replacing. The right amount varies from person to person, and from day to day.

This calculator gives you a simple starting point. It is a rule of thumb rather than a precise requirement, and you may need more or less than it shows.

How It Is Worked Out

The calculator starts with 35 ml for each kilogram of body weight a day. It then adds 500 ml for each hour of exercise, and another 500 ml for hot weather or summer. The total is shown in litres and in glasses, with a glass counted as 250 ml.

Hot weather is a big part of life across much of India. If you work outdoors, or you sweat a lot, you may well need more than this.

Spreading It Through the Day

Sipping regularly is easier on your body than drinking a lot at once. A glass when you wake up, one with each meal, and one or two between meals gets you most of the way for many people. Keeping a bottle nearby helps, especially at a desk. If you exercise, drink a little before, during, and after.

Fluids come from many places. Tea, milk, buttermilk, nimbu pani, coconut water, soups, and dal all count, and so do watery foods such as cucumber, watermelon, and oranges. Sugary drinks add calories, so plain water is still the best everyday choice.

When to Be Careful

Some people need a different amount, and sometimes less. With kidney or heart failure, your doctor may limit your fluids, so this calculator shows a message instead of a number. Some medicines also affect how your body handles water. Older adults may not feel thirsty even when they need a drink. If you are unsure, your doctor or a nutritionist can advise you.