Our water calculator will assist you in estimating how much water you require per day, including how much you will need to drink in the form of fluids (pure water or beverages). Our water intake calculator provides results in liters, milliliters, cups (equivalent to a standard glass), and ounces of water. Of course, these are estimates based on population averages, so consulting your physician or nutritionist before making changes to your water consumption or exercise routine is always recommended.

We use a rule that expresses water requirements in ml/kCal in relation to energy requirements. Energy requirements in each age and gender group are strongly evidence-based, based on extensive research that takes into account body size and activity level, which are important determinants of energy expenditure that must be met by dietary energy intake. Such expenditure measures employ highly accurate methods, and thus TDEE is based on solid data rather than the compromise inherent in Adequate Intake estimations for water.

Those same determinants apply to water utilization and balance, providing an argument for linking water/fluid intake recommendations to the more thoroughly researched energy recommendations. The extent to which water intake requirements are determined by energy intake and expenditure is unknown, but it has long been practiced in the clinical setting to provide 1 ml per kCal administered by a tube to patients who are unable to take in food or fluids. This is the basis for the output of this daily water intake calculator.

Water enters the human body through three main channels: water and other beverages, food, and as a byproduct of metabolic processes. Because water and beverages are only a portion of the input, our calculator will provide you with both your total water intake recommendation and how much of it you need to get through drinking fluids.