Water intake calculator
A simple daily water target from your body weight, with extra for exercise and hot weather.
Drink about
2.9 litres a day
In glasses (250 ml)
12
In 1 litre bottles
2.9
How the target is set
A common rule of thumb is about 35 ml of water per kg of body weight a day, which is the same figure SweatByte uses for its water tracker. For a 70 kg person that is about 2.5 litres.
The calculator adds extra for exercise (about 500 to 700 ml for an hour of training) and for hot or humid weather, when you lose more through sweat. Tea, milk, buttermilk, soups and water-rich fruit also count towards the total.
Signs you are drinking enough
Pale yellow urine and rarely feeling thirsty are good signs. Sip across the day instead of drinking a lot at once, and drink more around workouts. People with kidney, heart or other medical conditions, and pregnant women, should follow their doctor's advice on fluids.
Questions and answers
- How much water should I drink a day?
- About 30 to 40 ml per kg of body weight is a common guide, plus more when you exercise or the weather is hot.
- Does tea or coffee count?
- Yes, in moderation. Tea, coffee, milk and other drinks add to your fluid intake, though plain water is a good base.
- Can you drink too much water?
- Yes, though it is rare. Drinking very large amounts in a short time can be harmful, so sip steadily instead.
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Results are estimates for healthy adults and general information, not medical advice. Talk to a doctor or registered dietitian before big changes to your diet, especially if you have a health condition, take medicines or are pregnant.