How muscular
are you, really?
Find your Fat-Free Mass Index, the muscle-focused alternative to BMI, and see how close you are to the natural ceiling. Free, instant, no signup.
Not sure of your body fat percentage? The AI physique rater estimates it from photos.
21.6
Fit and athletic
86% of the 25 natural ceiling for men.
- Raw FFMI
- 21.5
- Lean mass
- 68.0 kg
FFMI is a guideline, not a verdict. Genetics, limb length, and measurement error all move it. Read the full breakdown in FFMI explained.
BMI says nothing about muscle. FFMI does.
18 to 20
Average for men. A solid, healthy base of muscle but untrained or early in lifting.
20 to 23
Clearly athletic. The range most consistent lifters reach after a few honest years.
23 to 25
Very muscular, approaching the drug-free ceiling research puts near a normalized 25.
FFMI, explained.
- What is FFMI?
- FFMI (Fat-Free Mass Index) measures how much lean muscle you carry relative to your height. Think of it as BMI for muscle: it is the standard way to gauge how muscular someone is, independent of how much fat they have.
- What is a good FFMI?
- For men, a normalized FFMI around 18 to 20 is average, 20 to 23 is fit and athletic, 23 to 25 is very muscular, and roughly 25 is the widely cited natural ceiling. For women the same scale runs about 4 to 5 points lower.
- What FFMI can you reach naturally?
- A landmark 1995 study (Kouri et al.) found drug-free lifters rarely exceed a normalized FFMI of about 25. A normalized FFMI well above 25 is uncommon without performance-enhancing drugs, though genetics and measurement error mean it is a guideline, not a hard wall.
- How is FFMI calculated?
- FFMI equals your lean mass in kilograms divided by your height in meters squared. Lean mass is your bodyweight minus fat mass. The normalized version adds a small height adjustment so taller and shorter lifters can be compared on the same scale.
- Do I need to know my body fat percentage?
- Yes. FFMI needs a body fat estimate to separate muscle from fat. A rough estimate is fine: the result only shifts slightly within a few percentage points. If you are unsure, the HyperBody physique rater estimates body fat from photos.
See where your muscle actually is.
FFMI is one number. The physique rater scores every muscle group and finds your weak points.
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