Calculate daily water intake recommendation
Built & maintained by Pappu Venkata Subbi Reddy, founder of Clacify · Formulas cited to their original published medical and research sources
Clacify's Water Intake Calculator estimates your recommended daily fluid intake based on body weight, using a baseline of 30 ml per kg of body weight, then adds a fixed bonus for your activity level (Low/Moderate/High) and climate (Normal/Warm/Hot). A 70 kg adult gets a 2.1L baseline; the tool adds up to 700 ml more for high activity and up to 700 ml more for hot climate, so the same person could range from 2.1L (sedentary, normal climate) up to 3.5L/day (highly active, hot climate). The tool shows the total daily water target broken down into its base, activity-bonus, and climate-bonus components. Actual needs vary based on diet, health conditions, and individual metabolism.
The Indian Council of Medical Research (ICMR) recommends 2.5–3 litres of water per day for sedentary adults in a moderate climate. In India's hot summers, during physical activity, or if you sweat heavily, requirements increase to 3–4 litres per day. A simple rule: drink enough to keep your urine pale yellow.
4 litres per day is safe for most healthy adults who are physically active in hot weather. However, drinking more than 4–5 litres in a short period can cause hyponatremia (low blood sodium), which is dangerous. For sedentary adults in normal conditions, 2.5–3 litres is sufficient.