FitCalc
Body composition

FFMI calculator

Measure how muscular you are for your height. Enter your weight, height and body-fat percentage, and see your fat-free mass index, normalized for height, with your category.


Fat-free mass indexLive
22norm.Excellent
FFMI · unadjusted21.9
Fat-free mass152.6 lb

Normalized FFMI adjusts for height. Around 25 is the rough ceiling for a natural, drug-free lifter, so values well above that are unusual.

How it works

How FFMI is calculated

First your body-fat percentage splits your weight into fat mass and fat-free mass. FFMI is that fat-free mass divided by your height squared, so it captures muscle relative to frame. The normalized version then adjusts to a standard height so people of different heights can be compared on the same scale.

It is a far better muscularity gauge than BMI, which counts muscle as if it were fat. The often-cited ceiling near 25 marks about the most a natural lifter tends to reach.

Questions

FFMI questions

What is FFMI?
Fat-Free Mass Index measures how much muscle you carry relative to your height, independent of body fat. Unlike BMI, it does not penalize you for being muscular, which makes it a better muscularity gauge for lifters.
What does normalized FFMI mean?
Taller people naturally get a slightly lower raw FFMI, so the normalized figure adjusts everyone to a standard 1.8 m height. The normalized number is the one to compare across people.
What is a good FFMI?
For men, around 18 to 20 is average, the low 20s is well-trained, and roughly 25 is the natural ceiling most drug-free lifters can reach. Women's values run lower on the same scale. The calculator labels where you fall.
Why do I need my body-fat percentage?
FFMI is built from your fat-free mass, so it needs your body-fat percentage to separate muscle from fat. If you do not know it, estimate it first with the body fat calculator.
Do you save my results?
No. Everything is calculated in your browser and nothing is stored or sent anywhere.