FFMI Calculator
Work out your fat-free mass index and see how it compares to the natural limit.
Average. Flat stomach, little visible definition.
US Navy method. Measure relaxed, straight around, in inches.
Neck just below the larynx. Waist at the navel.
Clear evidence of consistent resistance training.
What counts as a good FFMI?
FFMI measures how much lean mass you carry for your height, so unlike BMI it is not thrown off by body fat. The scale below follows the research that established roughly 25 as the practical ceiling for men training without drugs. Women are scored on their own lower scale, about three points below the men’s.
| Classification | Men | Women |
|---|---|---|
| Below average | Under 18 | Under 14 |
| Average | 18 to 20 | 14 to 16 |
| Above average | 20 to 22 | 16 to 18 |
| Athletic | 22 to 23.5 | 18 to 20 |
| Superior | 23.5 to 25 | 20 to 22 |
| Very high | 25 to 28 | 22 to 24 |
| Exceptional | 28 and above | 24 and above |
The height-adjusted figure adds 6.1 × (1.8 − your height in metres) to the raw number, so a shorter and a taller lifter can be compared fairly. The natural limit of 25 comes from a 1995 study of 157 male athletes, in which no drug-free lifter exceeded it.
Lean mass is what moves this number. Protein intake is the lever that builds it.
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