FFMI Calculator

Estimate fat-free mass index from weight, height, and body-fat percentage.

FFMI + normalized FFMI
Body-fat based
Category scale
FFMI estimate
Estimate fat-free mass index from height, weight, and body fat.
cm
kg
%
FFMI
22.0
Normalized FFMI
22.1
Lean mass
69.7kg
Normalized FFMI scale12 to 30
22.1
121820222530
Below average
12-18
Average
18-20
Above average
20-22
Excellent
22-25
Exceptional
25-30
CategoryExcellent

What FFMI measures

FFMI estimates lean mass relative to height, which helps compare muscularity independent of body-fat percentage.

Assumptions

Uses body-fat percentage to estimate lean mass, then divides by height squared. Normalized FFMI adjusts to a reference height of 1.8 m.

Use trend over time

Track FFMI over time with consistent body-fat measurement methods for more useful comparisons.