Daily Water Intake
Estimate how much water you need per day based on your body weight.
kg
Water per day2.6 L
Glasses (250ml)11
Baseline ≈ 35 ml per kg. Increase with exercise, heat or pregnancy.
How it works
How much water do you actually need in a day? The calculator gives a realistic estimate based on your body weight and how much you move.
As a starting point it uses about 35 ml of water per kilogram, and adds extra for every half hour of exercise. A 70 kg person needs roughly 2.4 litres without intense activity.
In heat, sweating or a workout the need rises — treat the estimate as a guide, not a strict rule.
Frequently asked questions
Does only plain water count?
Not only. Other drinks and the water in food also contribute to hydration, but plain water is still the best source.
Do I need more water when exercising?
Yes. You lose fluid through sweat, so add water according to how long and how hard you train.
Can I drink too much water?
Very rarely, but extreme intake in a short time can dilute blood sodium (hyponatraemia). For almost everyone, spreading normal amounts through the day is safe — thirst and pale urine are good everyday guides.