Water intake calculator
How much to drink a day, with extra for exercise and hot weather. Free, nothing leaves your browser.
Your water a day
An estimate for healthy adults, not medical advice. Kidney or heart condition, pregnant or breastfeeding? Ask your doctor.
How it works
The European Food Safety Authority sets adequate intakes of total water at 2.0 litres a day for women and 2.5 litres for men. About 80 % comes from drinks, the rest from food.
Exercise adds about half a litre per hour, and heat or heavy sweating more. Pale yellow urine is a simple everyday check.
Sources: EFSA, Scientific Opinion on Dietary Reference Values for water, EFSA Journal 2010;8(3):1459.