# 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.

## 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.

## Sources

- [National Academies. Dietary Reference Intakes for Water, Potassium, Sodium, Chloride, and Sulfate (2005)](https://nap.nationalacademies.org/catalog/10925)

Accurate as of November 12, 2026.

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revns gives training guidance, not medical advice.