What lean body mass is
Lean body mass is your weight minus fat: muscle, bone, organs and water. Without a body-fat measurement it is estimated from height and weight; the Boer formula is the one most often used clinically.
Boer — women: 0.252 × kg + 0.473 × cm − 48.3
Common questions
Why do the three formulas give different numbers?
Boer, James and Hume were each derived from different reference populations decades apart, so they weight height and weight slightly differently — expect a few kilograms of spread between them for the same person, all in the same ballpark.
Should I use this or the BMR calculator's Katch-McArdle option?
This one estimates lean mass from height and weight alone; Katch-McArdle needs a body-fat percentage as input and uses it to compute BMR. If you don't have a body-fat number yet, this calculator's estimate is a reasonable starting point to feed into it.
For general information only — not medical advice. Talk to a doctor about anything that concerns you.