Here you can calculate fat free mass index (FFMI) using only 3 parameters of your body: weight, height and body fat. If you don’t know the last indicator, you can use one of these calculators:
What is FFMI?
FFMI is the abbreviation of Fat Free Mass Index that means an amount of muscle mass in relation to height and weight of a human. It is an alternative to BMI which is considered to be more precise for well-trained people, including professional sportsmen and bodybuilders.
FFMI calculation
FFMI calculator uses quite difficult formula which includes the calculation of lean body mass:
Lean = Weight × (1.0 – (Body Fat / 100.0))
FFMI = (Lean / 2.2) / ((Height × 12.0 + Inches) × 0.0254)2
Adjusted FFMI = FFMI + (6.0 × (((Height * 12.0 + Inches) × 0.0254) – 1.8))
To simplify it we recommend using our fat free mass index calculator.
What is a good FFMI?
The norm of average FFMI depends on the gender:
| Description of the result | For men | For women |
| Below average | < 18 | < 15 |
| Average | 18 – 20 | 15 – 17 |
| Above average | 20 – 22 | 17 – 18 |
| Excellent | 22 – 23 | 18 – 19 |
| Superior | 23 – 26 | 19 – 21.5 |
| Suspicion of steroid use but might be attainable naturally | 26 – 28 | 21.5 – 25 |
| Steroid usage likely | > 28 | > 25 |
However, you may also meet another FFMI scale on the Internet.
