Pikkit

Lean Body Mass Calculator

Lean body mass from height and weight by Boer, James and Hume, or body fat %.

About this tool

Choose units and sex, then enter height and weight. The calculator shows lean body mass by three published formulas and the body fat percentage each implies. If you know your body fat percentage from a scan, calipers or a smart scale, enter it for a direct calculation at the top of the table.

How lean body mass is estimated

Lean body mass (LBM) is your weight minus fat: muscle, bone, organs, skin and water. With a known body fat percentage it's simple: LBM = weight Γ— (1 βˆ’ body fat %). Without one, regression equations estimate it from height and weight. The Boer formula (1984) for men is 0.407 Γ— weight in kg + 0.267 Γ— height in cm βˆ’ 19.2; for a man 178 cm tall weighing 82 kg it gives about 61.7 kg. The James formula (1976) and Hume formula (1966) use different coefficients, and each has a separate version for women. LBM is used to set protein targets, in the Katch–McArdle calorie formula and for dosing some drugs. Honest limits: the equations come from average populations, so they are less accurate for very muscular, very lean or obese people. The James formula in particular gives implausible results at high BMI. Not medical advice. The body fat calculator estimates body fat from tape measurements, the FFMI calculator turns lean mass into an index and the protein intake calculator uses it. How body fat percentage is estimated β€” and how much to trust each method compares measuring methods.

Frequently asked questions

What is a healthy lean body mass?

It depends on height and sex. Men are typically 75–90% lean and women 65–80%, which is a body fat of roughly 10–25% and 20–35%.

Is lean body mass the same as muscle mass?

No. Lean mass includes muscle plus bone, organs, skin and water; muscle is roughly half of it.

Which LBM formula is most accurate?

Boer is often preferred for adults of normal weight. A measured body fat percentage beats any formula.

Is my data saved?

No. The calculation runs in your browser and nothing is stored or sent.

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