Calculate your Fat-Free Mass Index to evaluate muscle development
| FFMI Range | Male Rating | Female Rating |
|---|---|---|
| < 15 | Low | Severely low muscle mass |
| 16 - 17 | Low | Below average muscle mass |
| 17 - 19 | Normal | Average muscle mass |
| 19 - 21 | Good | Above average muscle mass |
| 21 - 23 | Excellent | Well developed muscles |
| > 23 | Elite | Near natural limit or suspicious |
FFMI (Fat-Free Mass Index) is a metric used to evaluate muscle development. Unlike BMI, FFMI excludes body fat influence, more accurately reflecting muscle mass level. FFMI is particularly suitable for evaluating muscle development in fitness enthusiasts and athletes.
BMI only considers height and weight, unable to distinguish muscle from fat. A muscular athlete may have high BMI but actually be very healthy. FFMI excludes body fat, focusing on evaluating lean mass (mainly muscle), making it a more meaningful metric for fitness enthusiasts.
Lean Mass = Weight × (1 - Body Fat%/100)
FFMI = Lean Mass / Height²
Adjusted FFMI = FFMI + 6.1 × (1.8 - Height)