Body Water Percentage Calculator

Water is the most abundant substance in the human body, comprising 45-75% of total body weight depending on age, sex, and body composition. Total body water (TBW) includes both intracellular fluid (inside cells) and extracellular fluid (blood plasma, interstitial fluid, and other bodily fluids). This calculator estimates your body water percentage based on age, sex, and weight. Men typically have higher percentages (50-65%) than women (45-60%) because muscle tissue contains more water than fat tissue. Athletes and individuals with high muscle mass tend toward the higher end of the range, while those with higher body fat percentages tend toward the lower end. Understanding your body water percentage provides insight into hydration status and body composition. Note that this is an estimate - precise measurement requires bioelectrical impedance analysis or more advanced techniques.