Lean Body Mass Calculator

Formula

weight × (1 − body fat%)

Worked example

80 kg at 20% fat — 64 kg

Quick answer

What does the Lean Body Mass Calculator do?

Estimate lean body mass from body weight and body-fat percentage.

What is the Lean Body Mass Calculator?

Estimate lean body mass from body weight and body-fat percentage. Use it when you have the required inputs and want a deterministic, repeatable result with the calculation method visible.

How to use this calculator

Enter the values requested by the tool, keep units and time periods consistent, resolve any validation message, calculate, then review the primary answer together with the displayed formula and supporting values.

Formula and method

This calculator uses the deterministic formula weight × (1 − body fat%). Enter the required values, then review the displayed substitution and result breakdown to verify the calculation.

Worked example

80 kg at 20% fat 64 kg

Common mistakes to avoid

Check units, decimal points, percentages, signs, date/time order, selector choices, and rounding. For important decisions, verify the result against an independent source or qualified professional when appropriate.