Body Composition · 2026
Body Water Percentage Calculator How much of you is water?
Estimate your body water percentage using the Watson formula — the same one used in clinical research. Adults are typically 50–65% water.
50–65%
Adult Avg Range
78%
Infants
Watson
Clinical Formula
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Enter your details to estimate your body water.
How It Works
The Watson formula explained.
Published in 1980, the Watson formula is the gold standard for estimating Total Body Water (TBW).
The Formula
Male: TBW = 2.447 − (0.09156 × age) + (0.1074 × height in cm) + (0.3362 × weight in kg)
Female: TBW = −2.097 + (0.1069 × height in cm) + (0.2466 × weight in kg)
Result is in litres. Body water % = (TBW / weight in kg) × 100.
What's Healthy?
- Adult men: 50–65% (avg 60%)
- Adult women: 45–60% (avg 55%)
- Infants: up to 78%
- Elderly: tends to drop with age
Higher body fat = lower body water %. Athletic build typically has higher body water %.
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All tools are free, no signup, no email. Built using peer-reviewed formulas where applicable.