FFMI Calculator
Calculate Fat-Free Mass Index (FFMI) and height-normalized FFMI from weight, height, and body fat percentage. Supports metric (kg, cm) or imperial (lb, in).
FAQ for this calculator
- What is normalized FFMI?
- An adjustment that references 1.8 m height so shorter and taller lifters compare more fairly.
- How do I measure body fat?
- DEXA, hydrostatic, or skilled caliper tests beat visual guesses—garbage in, garbage out.
- FFMI vs BMI?
- BMI uses total weight; FFMI uses lean mass—better for muscular builds.
- Is high FFMI “unnatural”?
- Categories are population statistics, not judgments—genetics and training history vary widely.
How to use the FFMI calculator
Lean mass equals weight minus fat mass. FFMI compares lean mass to height squared, similar to BMI but for muscle.
- Choose metric or imperial units.
- Enter weight, height, and estimated body fat %.
- Read FFMI, normalized value, and category.
When to use this calculator
- Tracking recomposition during a cut.
- Comparing two DEXA readings months apart.
- Understanding normalized FFMI vs raw FFMI.
Examples & walkthrough
- 80 kg, 180 cm, 15% fat → FFMI in athletic range for many charts.
- Same lean mass, taller athlete → normalized FFMI adjusts upward.