FFMI Calculator
Calculate Fat-Free Mass Index.
Enter values to calculate your FFMI.
For athletes, bodybuilders, and fitness enthusiasts, tracking progress is about more than just the number on the scale. While BMI can give a rough idea of healthy weight, it famously fails to distinguish between fat and muscle. The Fat-Free Mass Index (FFMI) is a more advanced metric that solves this problem, providing a measure of how muscular you are relative to your height.
What is FFMI?
FFMI measures the amount of your lean body mass (everything in your body that isn't fat—muscles, bones, organs, water) in relation to your height. A higher FFMI indicates a more muscular physique. It's an excellent tool for tracking the effectiveness of a strength training program.
The FFMI Formula
Calculating your FFMI involves a few steps:
- Calculate Lean Body Mass (LBM):
LBM = Weight × (1 - (Body Fat % / 100)) - Calculate FFMI:
FFMI = LBM (kg) / (Height (m)²) - Calculate Normalized FFMI:
Normalized FFMI = FFMI + 6.1 × (1.8 - Height (m))
This adjustment accounts for the fact that taller individuals naturally have a structural advantage to carry more muscle mass. It normalizes the score to what it would be for someone of average height (1.8m or ~5'11").
Interpreting Your FFMI Score
The normalized FFMI score gives you a good idea of where your muscularity stands compared to the general population:
| FFMI (Men) | FFMI (Women) | Interpretation |
|---|---|---|
| 18-20 | 15-16 | Average |
| 20-22 | 16-18 | Above Average |
| 22-25 | 18-21 | Excellent |
| 26+ | 22+ | Suspiciously High (Possible steroid use) |
Research suggests that a normalized FFMI of around 25 is near the upper limit for men who do not use anabolic steroids. This makes FFMI a useful tool for setting realistic muscle-building goals.
Disclaimer: This FFMI calculator requires an accurate body fat percentage measurement. Use our Body Fat Calculator or get a professional measurement for the best results. The tool is for educational purposes and is not a substitute for professional health advice.
Enter values to see the results.
For athletes, bodybuilders, and fitness enthusiasts, tracking progress is about more than just the number on the scale. While BMI can give a rough idea of healthy weight, it famously fails to distinguish between fat and muscle. The Fat-Free Mass Index (FFMI) is a more advanced metric that solves this problem, providing a measure of how muscular you are relative to your height.
What is FFMI?
FFMI measures the amount of your lean body mass (everything in your body that isn't fat—muscles, bones, organs, water) in relation to your height. A higher FFMI indicates a more muscular physique. It's an excellent tool for tracking the effectiveness of a strength training program.
The FFMI Formula
Calculating your FFMI involves a few steps:
- Calculate Lean Body Mass (LBM):
LBM = Weight × (1 - (Body Fat % / 100)) - Calculate FFMI:
FFMI = LBM (kg) / (Height (m)²) - Calculate Normalized FFMI:
Normalized FFMI = FFMI + 6.1 × (1.8 - Height (m))
This adjustment accounts for the fact that taller individuals naturally have a structural advantage to carry more muscle mass. It normalizes the score to what it would be for someone of average height (1.8m or ~5'11").
Interpreting Your FFMI Score
The normalized FFMI score gives you a good idea of where your muscularity stands compared to the general population:
| FFMI (Men) | FFMI (Women) | Interpretation |
|---|---|---|
| 18-20 | 15-16 | Average |
| 20-22 | 16-18 | Above Average |
| 22-25 | 18-21 | Excellent |
| 26+ | 22+ | Suspiciously High (Possible steroid use) |
Research suggests that a normalized FFMI of around 25 is near the upper limit for men who do not use anabolic steroids. This makes FFMI a useful tool for setting realistic muscle-building goals.
Disclaimer: This FFMI calculator requires an accurate body fat percentage measurement. Use our Body Fat Calculator or get a professional measurement for the best results. The tool is for educational purposes and is not a substitute for professional health advice.