Understand your body composition

Lean Body Mass Calculator

Estimate how much of your body weight is lean mass using your weight and body-fat estimate.

Units

Body fat is required. If unknown, estimate it first.

Estimate Body Fat →

Lean mass is not the same as muscle mass

This two-compartment estimate subtracts calculated fat mass from total body weight. The remainder includes muscle, water, bone, organs, and other non-fat tissue.

Limits of the estimate

Any error in body-fat percentage carries directly into lean mass. FitCalc therefore requires a body-fat estimate rather than substituting a height-and-weight prediction that answers a different question.