This lean body mass calculator determines LBM based on age gender, weight and height in either English or metric measurements. You can read more on this subject below the form.

Age: *
Gender: *
Weight: *
Height: *
Age: *
Gender: *
Weight: *
Height: *

How does this lean body mass calculator work?

This is a health tool that evaluates a body parameter known as LBM, which is the lean body mass, through age, gender, weight and height. To make it easier for you to input your data you can use either the English or the metric tab so you can input either kg and cm or lbs and ft in. The result comprises of the LBM value found by employing three different formulas and then given in both the measurement units so you can quickly understand it. The three weight equations are described below. However, these are methods applied for users aged 15 or above as for children there is a more specific formula also described.

  • The Hume's LBM formula:

Male: Estimated LBM = 0.32810*Weight (in kg) + 0.33929*Height (in cm) - 29.5336
Female: Estimated LBM = 0.29569*Weight (in kg) + 0.41813*Height (in cm) - 43.2933

  • The Boer's LBM formula:

Male: Estimated LBM = 0.407*Weight (in kg) + 0.267*Height (in cm) - 19.2
Female: Estimated LBM = 0.252*Weight (in kg) + 0.473*Height (in cm) - 48.3

  • The James's LBM formula:

Male: Estimated LBM = 1.1*Weight (in kg) – 128*[Weight (in kg)/Height (in cm)]2
Female: Estimated LBM = 1.07*Weight (in kg) – 148*[Weight (in kg)/Height (in cm)]2

  • In case of children up to 14 years old no gender specific, the lean body mass calculator returns only one value which is calculated based on the Peter's formula presented below:

Estimated LBM = 3.8*[0.0215*(Weight in kg^0.6469)*(Height in cm^0.7236)]

Example calculations:

  • Adult female, aged 34 weighing 124lbs at a height of 5ft 4in. The result is
Estimated Lean Body Mass LBM in lbs LBM in kg
By Hume’s Formula 91.07 41.31
By Boer’s Formula 94.28 42.76
By James’s Formula 93.62 42.46
  •  Child, aged 10 weighing 20lbs at a height of 28.6 in. The result is
Estimated Lean Body Mass LBM in lbs LBM in kg
By Peter’s Formula 16.67 7.56

What is lean body mass?

This is the body mass that results by subtracting the body fat from the total body weight. Statistics show that this is usually around 60 to 90% of the body mass. Which means that the overall equation is: Body mass= Lean body mass + Body fat so the body fat percentage is on average 10 to 40%. Since it represents all but fat in the body it means that this accounts for organs, blood, bones, muscle and skin.

LBM as an index is used to analyze metabolic functions and in prescribing medication for metabolic disorders. It can also be used to keep track of weight loss and ensure it is being done without loosing any muscle mass instead of the targeted fat.


1) Hume R. (1966) Prediction of lean body mass from height and weight. J Clin Pathol; 19(4):389-91.

2) Fuchs RJ, Theis CF, Lancaster MC. (1978) A nomogram to predict lean body mass in men. Am J Clin Nutr. 31(4):673-8.

3) Boer P. (1984) Estimated lean body mass as an index for normalization of body fluid volumes in man.

4) Absalom AR, Mani V, DeSmet T,et al. Pharmacokinetic models for propofol-defining and illuminating the devil in the detail. Br J Anaesth 2009; 103:26-37

5) A. M. Peters, H. L. R. Snelling, D. M. Glass, N. J. Bird (2011) Estimation of lean body mass in children.

19 Jan, 2015