Water intake calculator: a daily starting point, including training
Reference intakes for total water, from food and drink, are about 3.7 litres a day for men and 2.7 litres for women, and roughly 80% of that comes from drinks. A practical starting point is about 30 to 35 ml per kg of body weight, plus about 0.5 litre per 30 minutes of sweaty training. Thirst and pale-yellow urine are good day-to-day guides.
- Drinks today
- 2.9–3.2 L
- a starting point; follow thirst
- Base
- 2.1–2.5 L
- 30–35 ml per kg
- For training
- +0.8 L
- about 0.5 L per 30 min
How it works
Base
Body weight × 30 to 35 ml gives a range for drinks on a normal day.
Training
Add about 0.5 L per 30 minutes of training, more in heat. Weighing before and after a long session shows your own sweat rate.
Questions
Does coffee count toward water?
Yes, mostly. Moderate amounts of coffee and tea contribute to fluid intake.
Can you drink too much water?
Yes. Very large amounts in a short time, especially in long endurance events, can lower blood sodium. Drink to thirst and include salt on long, hot sessions.
Do I need more water with a high-protein diet?
Slightly. Following thirst and urine colour covers it for most healthy people.
Related calculators
Sources
Accurate as of November 12, 2026. Training and nutrition guidance only, not medical advice. See a clinician for symptoms, injury or a medical condition.
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