Lean Body Mass Calculator
Your body weight minus fat, estimated with three prediction formulas.
Lean body mass covers muscle, bone, organs and body water. It has direct uses in programme design and in working out protein needs.
Fill in your details and press calculate — your result will appear here.
Formula and method
Three regression equations from height, weight and sex. Boer is the default because it was derived for clinical use and is the most widely cited.
Formula used
Boer (default), James or Hume prediction equations
Assumptions and limits
- These are predictions from height and weight, not measurements. If you know your actual body fat, computing it directly is more accurate.
- The three formulas disagree by several kilograms for the same body, and that spread is itself informative.
Scientific sources
Boer P. “Estimated lean body mass as an index for normalization of body fluid volumes in humans.” Am J Physiol. 1984;247(4):F632-F636.
James WPT. Research on Obesity: A Report of the DHSS/MRC Group. HMSO, London, 1976.
Hume R. “Prediction of lean body mass from height and weight.” J Clin Pathol. 1966;19(4):389-391.