Lean Body Mass Calculator

Calculate lean body mass (LBM) from weight and height with the Boer formula — no calipers or body scan needed.

Lean body mass (LBM)
61.4 kg
Boer formula
Fat mass
18.6 kg
Fat mass in %
23.2%
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How to use the lean body mass calculator

  1. Enter your weight in kilograms.
  2. Enter your height in centimeters.
  3. Choose your sex — the Boer formula uses different coefficients for men and women.

The Boer formula

Lean body mass (LBM) is your total weight minus fat mass: muscle, bone, organs, water, and everything else that isn't adipose tissue. The 1984 Boer formula is one of the most widely used methods for estimating LBM from weight and height alone:

Men: LBM = 0.407 × weight + 0.267 × height − 19.2
Women: LBM = 0.252 × weight + 0.473 × height − 48.3

The advantage of the Boer formula is that it doesn't require calipers, a DEXA scan, or other measurement methods that aren't available at home — just weight and height. It's most accurate for adults with weight and body composition in the normal range, and less precise at extreme obesity or very low body fat percentages.

Note: This is a mathematical formula based on average data, not a direct measurement of your body composition. Actual methods like DEXA scanning or hydrostatic weighing give more accurate individual figures.
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Frequently asked questions

What's the difference between lean body mass and muscle mass?

Lean body mass includes everything that isn't adipose tissue — muscle, bone, organs, blood and water. Muscle mass is just one part of this. LBM is therefore always higher than your pure muscle mass.

Why does the formula differ for men and women?

Because men and women on average have different body composition at the same weight and height — partly due to differences in bone mass, muscle mass, and typical fat distribution. The Boer formula therefore uses sex-specific coefficients for better accuracy.

How accurate is this formula?

The Boer formula is validated against more precise methods and is considered one of the more accurate formulas using only weight and height, but it's still an average estimate. Individual body composition can vary, especially for athletes or people with unusual muscle-to-fat distribution.

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