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Lean Body Mass Calculator

Estimate the weight of fat-free tissues, including muscle, bone, organs, and water.

Enter your details

All calculations happen in your browser. No information is saved.

Unit System
Gender

Your Lean Body Mass Result

Estimated lean body mass

Practical interpretation

Important: Estimate only—not medical advice.

How the Lean Body Mass Calculator works

Formula: Male LBM = 0.407W + 0.267H − 19.2; female LBM = 0.252W + 0.473H − 48.3.

The Boer equations estimate lean mass from weight in kilograms and height in centimeters.

Assumptions and limits: This is not a direct body-composition measurement and may be less accurate at body-size extremes. Results are estimates for education and planning, not medical advice.

How to use your result

Use the result as a starting point, not a pass-or-fail score. Keep your inputs consistent, observe relevant trends over time, and adjust only when the trend—not one day—shows the estimate does not fit your needs.

Body measurements and equation-based targets always contain uncertainty. If your result conflicts with symptoms, a diagnosis, medication guidance, pregnancy needs, an eating-disorder recovery plan, or instructions from your care team, follow your qualified health professional.

Frequently Asked Questions

What does the Lean Body Mass Calculator calculate?

It estimates estimate fat-free body mass with the boer equation. from the information you enter. It is a planning and screening estimate, not a diagnosis or individualized medical prescription.

Which formula does this Lean Body Mass Calculator use?

This tool uses Male LBM = 0.407W + 0.267H − 19.2; female LBM = 0.252W + 0.473H − 48.3.. The formula and every adjustment are shown on this page so you can understand the assumptions.

Can I use metric or imperial units?

Yes. Choose metric or imperial before entering body measurements. Imperial values are converted to kilograms and centimeters before the formula runs.

How accurate is this Lean Body Mass Calculator?

Population equations provide useful starting estimates but cannot measure your individual physiology. This is not a direct body-composition measurement and may be less accurate at body-size extremes.

Who should not rely on this result alone?

Children, pregnant or breastfeeding people, competitive athletes with specialized needs, and anyone managing a medical condition should seek advice from a qualified health professional.

How often should I recalculate?

Recalculate when your body weight, activity, goal, or other relevant input changes meaningfully. Small day-to-day fluctuations generally do not warrant a new target.

Why might my result differ from another calculator?

Calculators may use different equations, activity factors, rounding rules, or definitions. Compare the documented methods rather than assuming one number is exact.

Is this result medical advice?

No. This educational estimate cannot account for diagnoses, medications, laboratory results, or clinical fluid and nutrition restrictions. Consult a licensed professional for personal medical advice.

Scientific References

  1. Estimated lean body mass as an index for normalization of body fluid volumes in humans American Journal of Physiology
  2. Body mass index (BMI) World Health Organization
  3. ACSM Guidelines for Exercise Testing and Prescription American College of Sports Medicine

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