Total Body Water

What this calculator does

Total Body Water helps you estimate estimated total body water percentage. The result is computed instantly in your browser and is intended for clinicians, students, and informed patients reviewing screening values.

Formula and variables

Displayed formula: Watson formula

The engine evaluates: TBW (L). Variable names match the input field keys so you can trace each step from entry to output.

How to use this tool

1. Open the Total Body Water and enter your values using the units shown beside each field.
2. Review that inputs are within the typical physiological range before you calculate.
3. Read the result together with the interpretation notes below and your local clinical context.

How to interpret the result

Compare the calculated value with established reference intervals for your population. A single number rarely defines management—combine it with symptoms, trends over time, medications, and physical examination. If the result is unexpected, repeat the calculation with verified inputs before acting on it.

Clinical context

Hydration and training targets adjust for climate, sweat rate, fever, and kidney disease. Increase fluids cautiously when heart failure or hyponatremia risk exists.

Limitations and disclaimer

This tool supports education and clinical triage only. It does not replace professional medical advice, diagnosis, or treatment. Reference ranges vary by laboratory, age, pregnancy status, and comorbidity. Always confirm critical decisions with institutional protocols and qualified clinicians.

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