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Body Water Percentage Calculator

Estimated total body water percentage using the Watson formula.

years

Formula: Watson formula

Worth Knowing

The Watson formula estimates total body water from height, weight, age, and sex, and the result is revealing: water typically makes up 50–65% of body weight, with lean tissue holding far more of it than fat. That's why leaner and more muscular people show higher body-water percentages, and why the figure tends to decline with age as muscle mass falls. Hydration status, recent meals, and exercise all shift real body water, so treat the estimate as a baseline.

How to Use

  1. Enter Gender into the first field of the Body Water Percentage Calculator.
  2. Fill in the rest: Age, Height, Weight.
  3. Your result appears instantly as you type — there's no submit button or page reload.

Formula

Watson formula

Frequently Asked Questions