Tools · Calculators · Health Last update: Nov 7, 2026

Lean Body Mass Calculator

Estimate your lean body mass — everything except fat — from your height, weight and sex.

Sex
ftin
lb
—

For healthy adults. These are estimates, not medical advice. Ask a doctor or dietitian about your own targets — especially if you are pregnant, have a health condition or are under 18.

Lean body mass formulas

Boer (men): 0.407 × weight + 0.267 × height − 19.2
Boer (women): 0.252 × weight + 0.473 × height − 48.3
(weight in kg, height in cm)

Example: a man of 175 cm and 75 kg has a lean body mass of about 58.1 kg — 77% of his weight.

What lean body mass is used for

Lean mass includes muscles, organs, bones and water. It is used to dose some medicines, in the Katch-McArdle BMR formula and to set protein targets. The calculator also shows the James and Hume formulas for comparison.

Frequently asked questions

What is lean body mass?

Your total weight minus body fat: muscles, bones, organs, skin and water.

How accurate are lean body mass formulas?

They give population averages. Body scans such as DEXA measure it directly.