While 30% water content might seem plausible, it significantly underestimates the actual amount of water in the human body. At around 60%, water makes up more than half of our body composition. Only certain body tissues — like fat or bone — may approach 30% water, but overall, that number is too low. Believing the human body is only 30% water can minimize the importance of hydration and lead to poor health habits. Water is vital to the function of every organ system, including digestion, circulation, brain performance, and temperature regulation. People who underestimate the body’s water needs may not prioritize hydration, which can lead to chronic dehydration and related symptoms such as fatigue, brain fog, and muscle cramps. While the percentage varies slightly by individual, especially based on muscle-to-fat ratio, 60% remains the accurate and medically accepted average for healthy adults.