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About the Lean Body Mass Calculator
This calculator estimates your lean body mass, which is your total weight minus fat mass. It also shows your lean mass as a percentage of body weight, so you can track muscle and tissue changes over time.
The tool applies the standard Boer formula, which estimates lean mass from weight and height, with separate equations for men and women. If you know your body fat percentage, the calculator can use that instead and compute lean mass directly. Enter values in one unit system to keep results consistent. For best accuracy, weigh yourself at the same time each day, ideally in the morning before eating.
- Enter your current weight and choose kilograms or pounds.
- Add your height and select your sex.
- Read your lean body mass and lean mass percentage in the results.