Water is the lifeline of the body — essential for every cell and tissue to perform its vital functions. It makes up about 60% of human body mass and 90% of blood. Since the body loses water through urine, sweat and even breathing, drinking enough of it daily is essential to prevent dehydration.

How the calculation works

The calculator uses the most common guideline: the body needs roughly 30–35 ml of water per kilogram of body weight per day. A person weighing 70 kg, for example, needs about 2.1–2.5 litres — more with physical activity, hot weather, breastfeeding and pregnancy.