Lean Body Mass Calculator
Enter your height and weight to estimate your lean mass and fat mass.
Fill in the form and hit calculate to see your results here.
Your body composition
This uses the Boer formula, which estimates lean mass from height and weight alone, without a tape measure.
What lean body mass includes
Lean body mass is everything that isn't fat — muscle, bone, organs and water. It's a useful baseline for setting protein targets or tracking changes in body composition.
Why the Boer formula
It's one of the more widely validated equations for estimating lean mass from just height, weight and sex — no tape measure or calipers required, though it's still an estimate.
Using this for protein targets
Some people prefer setting protein intake relative to lean mass rather than total bodyweight, especially at higher body fat levels — try the Protein Calculator with this number.
The formula
# Boer formula Men: LBM(kg) = 0.407 × weight(kg) + 0.267 × height(cm) - 19.2 Women: LBM(kg) = 0.252 × weight(kg) + 0.473 × height(cm) - 48.3 # Fat mass Fat mass = weight - LBM
Common questions
This estimates lean mass directly from height and weight, without needing tape measurements — it's quicker but generally a little less precise than the circumference-based method.
They use different estimation approaches — this one is weight/height-based, the Body Fat Calculator is circumference-based. Small differences between methods are normal and expected.
Yes — lean body mass is also useful on its own for setting a protein target, even if you're not otherwise tracking body composition.
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