FFMI Rechner
Eine muskelbewusste Alternative zum BMI.
Gib deine Daten ein, um dein Ergebnis zu sehen.
What FFMI actually measures
FFMI is your fat-free mass index. It measures how much lean, non-fat mass you carry relative to your height. Where BMI lumps muscle and fat together, FFMI removes the fat first and looks only at what is left: muscle, bone, organs, and water.
That makes FFMI the muscle-aware alternative to BMI. For anyone who trains, the difference is the whole point.
Why FFMI beats BMI for muscular people
BMI cannot tell muscle from fat, so it routinely flags lean, muscular people as overweight. A fit lifter and a sedentary person can share the same BMI and have completely different bodies. FFMI does not make that mistake, because it counts only lean mass. If BMI has ever called you overweight despite low body fat, compare it against your BMI result and you will usually see the gap.
How FFMI is calculated
FFMI needs two things: your weight and your body fat percentage. First you find lean mass, then you scale it to your height.
lean mass (kg) = weight × (1 - body fat %) FFMI = lean mass (kg) / height (m)²
For example, someone 1.80 m tall weighing 80 kg at 15 percent body fat has 68 kg of lean mass, giving an FFMI of 68 / (1.80 × 1.80) = 21.0. Because the result depends on body fat, an accurate body fat figure matters. If you are unsure of yours, start with the body fat calculator first.
How to read your number
The ranges below are for men. Women carry more essential fat and less muscle on average, so a healthy female FFMI runs roughly 3 to 4 points lower across the board.
| FFMI (men) | Interpretation |
|---|---|
| 16-18 | Below average |
| 18-20 | Average |
| 20-22 | Above average, fit |
| 22-23 | Athletic, well-muscled |
| 23-25 | Near the natural limit |
| 25+ | Unusual without enhancement |
The natural limit and what is realistic
The natural FFMI ceiling for men is widely cited at about 25, drawn from drug-tested lifters. Most men who train seriously for years land between 22 and 24. Reaching 23 or 24 naturally takes patience and consistency, and progress slows the closer you get. An FFMI above 25 is unusual without enhancement. Treat the limit as a horizon, not a target you are failing to hit.
Why FFMI is the metric that catches muscle loss
This is where FFMI earns its place. On any weight-loss journey, including GLP-1 medications, the scale falls but it does not tell you what you are losing. Some of that loss is often muscle, and generic weight apps simply cannot see it. FFMI and body fat percentage are exactly the two numbers those apps ignore, and they are the two that reveal whether you are protecting your muscle.
The fix is to track FFMI over time rather than reading it once. If your weight drops while FFMI holds steady, the loss is coming from fat, which is the goal. If FFMI slides down with the scale, you are shedding muscle and should adjust your protein and training. Log it every few weeks in the muscle tracker so you see the trend, not just a single number.
Häufig gestellte Fragen
What is a good FFMI?
For men, an FFMI around 18 to 20 is average and 20 to 22 is above average and fit. From 22 to 23 you are athletic and well-muscled, and 23 to 25 sits near the natural limit. Women typically run 3 to 4 points lower, so a good FFMI for a woman is often around 15 to 18. Body fat percentage adds the rest of the picture.
What is the natural FFMI limit?
The natural FFMI limit for men is widely cited at about 25, based on data from drug-tested lifters. Most men who train hard for years settle somewhere between 22 and 24. An FFMI above 25 is unusual without enhancement. Genetics, height, and training age all shift where your own ceiling falls, so treat 25 as a guide, not a hard wall.
What is the difference between FFMI and BMI?
BMI uses only height and weight, so it cannot tell muscle from fat and often flags muscular people as overweight. FFMI, the fat-free mass index, strips out fat first and measures only your lean mass relative to height. That makes FFMI the muscle-aware alternative to BMI and a far better read for anyone who trains or wants to protect their muscle.
How do I calculate FFMI for women?
The FFMI formula is the same for women and men: find your lean mass, then divide by height in metres squared. The interpretation differs. Women carry more essential fat and less muscle on average, so a healthy female FFMI runs roughly 3 to 4 points below the male ranges. Read your number against female-adjusted bands rather than the male table.
How can I increase my FFMI?
FFMI rises when you add lean mass or hold lean mass while losing fat. Progressive resistance training, enough protein, and adequate recovery build muscle over time. During weight loss, the goal is to keep FFMI steady so the scale drops from fat, not muscle. Track FFMI every few weeks, because gains in lean mass are slow and easy to miss day to day.
Do I need my body fat percentage to calculate FFMI?
Yes. FFMI is built on lean mass, and lean mass is your weight minus your fat. So you first need a body fat percentage to separate fat from the rest. A measured or well-estimated body fat figure gives an accurate FFMI, while a rough guess gives a rough result. The better your body fat number, the more trustworthy your FFMI.
Weiterlesen
Der FFMI setzt deine fettfreie Masse ins Verhältnis zu deiner Größe und bestraft Muskeln daher nicht wie der BMI. Hier erfährst du, was er bedeutet und wie du ihn liest.
GLP-1-Medikamente führen zu echtem Gewichtsverlust, doch ein großer Teil davon kann Muskulatur sein. Hier erfährst du, warum das passiert und wie du deine fettfreie Masse schützt.