Back to all calculators

Health & fitness

Lean body mass calculator

Calculate lean mass from weight and body fat percentage.

Your result

Complete the fields and calculate.

Calculation method and formula

Body weight [kg] × (1 − Body fat percentage [%] ÷ 100)

Understand the inputs

Body weight
Unit: kg. Use a measured value or your own assumption.
Body fat percentage
Unit: %. Use a measured value or your own assumption.

Assumptions and limitations

All circumference measurements must use the same unit. Errors in estimated body fat carry into derived values; these values are not a medical diagnosis.

The formula uses the specified units. Displayed numbers are rounded; whole packs, item counts and full time periods may also be rounded within the calculation.

Worked example

Illustrative values. Replace them with your own inputs for your calculation.

Body weight
75 kg
Body fat percentage
18 %
Example result61.5 kg

The result is based directly on your entries.

Model revision: October 17, 2026 · How CleverCalc works

FAQ

Frequently asked questions

How does Lean body mass calculator work?+

Body weight [kg] × (1 − Body fat percentage [%] ÷ 100). All circumference measurements must use the same unit. Errors in estimated body fat carry into derived values; these values are not a medical diagnosis.

What assumptions should I consider for this result?+

All circumference measurements must use the same unit. Errors in estimated body fat carry into derived values; these values are not a medical diagnosis. The formula uses the specified units. Displayed numbers are rounded; whole packs, item counts and full time periods may also be rounded within the calculation.

How accurate is the result?+

The formula uses the specified units. Displayed numbers are rounded; whole packs, item counts and full time periods may also be rounded within the calculation. Health values are general information, not a diagnosis or personal treatment recommendation.

Is this calculator free?+

Yes. Calculations and PDF export work without an account or registration.

What happens to my inputs?+

Calculations run in your browser. Results are saved locally only when you add them to My results; favourites and history are also local. Shared links contain your values. The currency tool requests the selected currencies from its rate provider without sending your amount.

Related document on CleverDocuFree document templates and practical PDF tools – directly in your browser with no sign-up.