Water Intake Calculator
See how much water you need each day based on your body weight, how long you train and the weather.
Enter your details to see your result.
How the water intake calculator works
A common sports-nutrition guideline is about 35 ml of fluid per kg of body weight per day as a baseline. On top of that we add what you lose through sweat:
Water (ml) = 35 × weight (kg) + 350 ml per 30 min of training + 500 ml if hot or humidExample: 70 kg, 1 hour of training in a hot climate → 2,450 + 700 + 500 = 3.65 litres a day.
Reading your result
The result counts all drinks — water, milk, tea, coffee and your protein shake. Food adds roughly another 20% of your fluid intake, especially fruit, vegetables, dal and curd.
The easiest check is your urine: pale straw colour means you’re well hydrated; dark yellow means drink more.
Tips & limitations
- Drink 400–600 ml about two hours before training, then sip through your session.
- After long or very sweaty sessions, add electrolytes (sodium in particular) to replace what you lose.
- Creatine users: drink a little extra, as creatine pulls water into muscle.
- Spread intake through the day — keep a bottle visible at your desk.
Frequently asked questions
How much water should I drink a day?
Most adults need roughly 30–40 ml per kg of body weight, plus more for exercise and hot weather. For a 70 kg person, that’s around 2.5 litres on a rest day.
Does tea or coffee count?
Yes. Moderate amounts of tea and coffee hydrate you nearly as well as water. Alcohol does not count.
Can I drink too much water?
Yes, though it’s rare. Drinking several litres within a few hours without electrolytes can dangerously lower blood sodium. Spread your intake over the day.
Do I need more water when taking creatine or protein?
A little. Higher-protein diets and creatine both slightly raise your fluid needs, so aim for the upper end of your range.
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These calculators give estimates for general fitness guidance only and aren’t medical advice. Speak to a doctor before making major diet or training changes, especially if you are pregnant, under 18 or have a medical condition.