How Much Water Do You Need?
The common guideline is 35 ml per kg of body weight per day. Active individuals and those in hot climates need more.
Base Water (ml) = Body Weight (kg) × 35
Activity addition: +300–600 ml per hour of exercise
Factors That Increase Water Needs
- Exercise: Add 500 ml for every hour of moderate exercise
- Hot weather: Add 500–1000 ml in hot/humid conditions
- Illness: Fever, vomiting, diarrhoea increase fluid loss
- Pregnancy/Breastfeeding: Add 300–700 ml/day
Does coffee count as water intake?
Partially. Coffee and tea contribute to hydration but caffeine has a mild diuretic effect. Plain water, milk, and herbal teas count fully. Sugary drinks are not ideal hydration sources.
Can you drink too much water?
Yes — overhydration (hyponatremia) can occur if you drink excessive amounts rapidly. For most healthy adults, the kidneys can process about 1 litre per hour.