🧍 Lean Body Mass Calculator

Lean Body Mass Calculator

Result

How It Works

Estimate lean body mass from body weight and body fat percentage. Use the estimate as a general starting point and review the assumptions behind it. Use Lean Body Mass Calculator as a general estimate from the measurements and assumptions you enter.

The result is most useful when the inputs match the definitions used by this calculator. For this tool, the underlying method is: LBM = Body Weight × (1 − Body Fat % / 100). Compare the output with the worked example, then change one meaningful input at a time to see how the result responds.

Understanding Lean Body Mass

Lean Body Mass is a general health or fitness estimate based on the measurements and assumptions requested by the calculator. Health estimates are not diagnoses and can differ from an individual's actual needs or measurements. Review the lean body mass inputs and units before relying on the result.

When to Use This Calculator

Use Lean Body Mass Calculator as a general estimate from the measurements and assumptions you enter.

Practical tip: For this Lean Body Mass Calculator, use the result as a starting estimate and change one measurement or activity assumption at a time so you can see how sensitive the estimate is.

Formula

LBM = Body Weight × (1 − Body Fat % / 100)

Example

At 80 kg and 20% body fat, estimated lean body mass is 64 kg.

Frequently Asked Questions

The calculator applies the method shown on the page to the health or fitness inputs you provide. It is an estimate, not a measurement of every aspect of an individual’s health.
Yes. Formulas simplify complex individual factors, so the same calculated value does not necessarily imply the same needs or health status.
Use it as a general informational estimate and consider the assumptions behind the formula. For medical concerns or personal treatment decisions, appropriate professional guidance is more reliable than a calculator alone.