About this water intake calculator
A common estimate is 30–35 ml of water per kilogram of body weight. This tool uses 33 ml/kg as the default recommendation and shows the 30–35 ml/kg range; add roughly 350 ml for every 30 minutes of exercise. For example, a 70 kg adult with no exercise needs about 2.31 L per day (range 2.10–2.45 L).
Real needs also depend on temperature, humidity, diet and sweating. During pregnancy or breastfeeding, or with kidney or heart conditions, follow medical advice on fluid intake. Results are for general reference only and are not medical advice; the calculation runs locally in your browser.