How to Calculate Your Daily Water Intake

Daily water intake can be calculated quite simply. For people with a normal weight, it is usually recommended to drink 25–30 milliliters of liquid per kilogram of body weight. For example, a person weighing 60 kilograms needs about 1.8 liters of liquid per day.

If a person’s actual weight is above normal and there is no goal to lose weight, the calculation is based on the so-called ideal weight rather than current weight. This can be estimated with the formula: height in centimeters minus 100. For a height of 170 cm, the ideal weight is about 70 kilograms, and the calculation is done using this value. People who plan to lose weight need slightly more liquid, around 40 milliliters per kilogram of ideal weight.

These recommendations include not only plain water, but all fluids consumed during the day, such as tea, coffee, soups, juices, and even water from fruits. However, it is preferable that drinking water makes up at least half of the total intake and ideally remains the main source.

There are also important nuances. Sweet carbonated drinks and alcohol are not considered healthy fluids and are more like food. People with kidney, heart, or high blood pressure conditions may need completely different volumes as prescribed by a doctor. During colds or any inflammatory processes, the body requires more fluids. Coffee drinkers should keep in mind that this beverage increases water excretion, so it is beneficial to drink one or two additional glasses of plain water.