Lean Body Mass Calculator

Use this Lean Body Mass Calculator to estimate the portion of body weight that is not stored body fat. The calculator uses the Boer formula and can also calculate lean mass from an entered body-fat percentage.

Calculation Methods

Boer formula for males:

LBM = 0.407 × weight (kg) + 0.267 × height (cm) − 19.2

Boer formula for females:

LBM = 0.252 × weight (kg) + 0.473 × height (cm) − 48.3

If body-fat percentage is known:

LBM = body weight × (1 − body fat % ÷ 100)

Example

For an 80 kg male who is 180 cm tall:

LBM = (0.407 × 80) + (0.267 × 180) − 19.2

LBM ≈ 61.4 kg

If the same person has an estimated body fat percentage of 15%:

LBM = 80 × 0.85 = 68 kg

The methods can give different estimates because they use different assumptions.

Important Note

Lean body mass is not the same as muscle mass. It includes muscle, water, organs, bone, and other non-fat tissues. Formula results are estimates rather than direct body-composition measurements.

Source

• Boer — Estimated Lean Body Mass as an Index for Normalization of Body Fluid Volumes