Water Intake Calculator
Work out how much water you should drink each day, with your training factored in.
Your results
Shop hydrationHow much water should you drink a day?
This water intake calculator estimates your daily fluid needs from your body weight and training time. Hydration affects strength, endurance and focus more than most people realise — losing just 2% of body weight as fluid measurably reduces performance.
How it works
The base recommendation is 35 ml per kilogram of body weight per day — a widely used clinical guideline that lands close to the European Food Safety Authority's adequate intakes (2.5 L/day for men, 2.0 L/day for women, from all sources). On top of that we add 350 ml per 30 minutes of exercise to cover sweat losses, in line with sports-medicine fluid replacement guidance.
Frequently asked questions
Does coffee count toward my intake?
Yes. Caffeinated drinks are mildly diuretic but still hydrate on net. Food also contributes roughly 20% of most people's fluid intake — soups, fruit and vegetables all count.
Should I drink more when taking creatine?
Creatine pulls water into your muscle cells, so staying well hydrated is sensible — this calculator's output is a good baseline. There's no need to force extreme amounts.
Can you drink too much water?
Yes — drinking many litres in a short window can dilute blood sodium (hyponatremia), which is dangerous. Spread intake through the day and include electrolytes around long, sweaty sessions.
References
- EFSA Panel on Dietetic Products, Nutrition, and Allergies. Scientific Opinion on Dietary Reference Values for water. EFSA Journal. 2010;8(3):1459.
- Sawka MN, Burke LM, et al. American College of Sports Medicine position stand: Exercise and fluid replacement. Med Sci Sports Exerc. 2007;39(2):377–390.
Related
These results are estimates for healthy adults and are not medical advice. Consult a health professional before making major changes to your diet or training.
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