From Body Fat to Lean Mass

This lean mass calculator takes your body weight and body fat percentage and splits them into fat mass and lean mass: fat = weight × fat%, lean = weight − fat. It is the direct, measurement-based method — the same arithmetic a DEXA report summarizes.

The Height Cross-Check

Entering height adds the Boer anthropometric estimate as a second opinion. A large gap between the two suggests your body fat measurement may be off — the direct number and the population formula should broadly agree.

Tracking Progress

Body weight alone cannot tell you whether you gained muscle or fat. Tracking lean mass keeps goals honest: a successful cut drops fat mass while preserving lean, and a successful bulk adds lean while limiting fat gain.