Water intake
Daily water target from body weight and activity level.
40 ml per kg of body weight at this activity level.
Assuming a 250 ml glass.
Drink to thirst, not to the number. The estimate includes water from food. Increase noticeably in heat or during long training; consult a doctor if you have kidney, heart, or fluid-balance conditions.
About this calculator
EFSA's adequate-intake reference for adults is around 30–35 ml/kg/day at rest; physical activity, heat, and high-fibre or high-protein diets push the need higher. This calculator scales from 30 ml/kg for sedentary days up to 50 ml/kg for very active ones. Food (vegetables, fruit, soup) usually covers 20–30% of intake — the figure here is total water, not just what you drink from a glass.
Common questions
Does food count toward the target?
Yes — the figure is total water, not just liquids. Vegetables, fruit, and soup typically cover 20–30% of daily intake. If your diet is rich in fresh produce, you can comfortably hit the target without drinking pure water all day.
What about coffee and tea?
They count. The old 'caffeine dehydrates you' claim doesn't hold up at normal intakes — moderate coffee and tea contribute net positive fluid. Alcohol is genuinely dehydrating; subtract a glass of water per standard drink mentally.
Can I drink too much water?
Yes — hyponatraemia (low blood sodium) is a real risk during very long endurance events when you replace sweat with plain water. For everyday life, healthy kidneys handle 800–1000 ml/hour comfortably; getting there from this calculator is essentially impossible.