FFMI Calculator
Use our FFMI calculator to calculate your fat-free mass index. FFMI is a measurement of someone's muscularity, based on their height, and is much more indicative of muscularity than BMI is. You can use our FFMI calculator to determine your natural muscular potential, and track your muscular gains over time.
Your FFMI Result
What is FFMI?
FFMI stands for Fat-Free Mass Index. FFMI is a calculation used in the same way that BMI is used to measure the weight of someone compared to their height, except FFMI measures fat-free mass rather than total mass. As such, FFMI is much better at reflecting an individual's muscularity than BMI is, which is why a lot of bodyBuilders and gym-goers use the FFMI calculator to measure their muscular potential, and where they stand compared to others.
FFMI was originally conceived in a study by Kouri et al, in 1995, which determined that natural bodybuilders have an FFMI of approximately 25, whereas those who use anabolic steroids to enhance their muscle mass typically have an FFMI above the natural FFMI maximum.
FFMI Calculator - How to Use
To use our FFMI calculator, all you need to do is select your gender, enter your age, height in inches, weight in pounds, and body fat percentage, and click calculate to get your FFMI score.
- Male or Female - Select your gender
- Age - enter your age e.g. 25 years of age
- Height (Inches) - enter your height in inches e.g. 70 inches
- Weight (lbs) - enter your current weight in pounds e.g. 180lbs
- Body Fat % - enter your current body fat percentage e.g. 15%
- Click the 'Calculate FFMI' button to get your result
FFMI Calculator - Background & Formula
FFM, or Fat-Free Mass, can be calculated using the following formula:
FFM = Weight X (1 - (Body Fat / 100))
Say you're a 5'10 male who weighs 180lbs at 15% body fat. Using the formula below, we can calculate your FFM:
FFM = 180 X (1 - (15/100)) = 180 × 0.85 = 153 lbs
You can use the FFM to determine your FFMI using the formula shown below.
FFMI = FFM / (Height in meters) 2
First, let's convert 70 inches into meters, by multiplying it by 0.0254.
Height in meters = 70 X 0.0254 = 70 × 0.0254 = 1.778 meters.
Now, let's calculate your FFMI score:
FFM I = 153 / (1.778) 2 = 153 / 3.161 = 48.4 (this is an example FFMI score, the actual results are usually lower for males).
Note: Again, this formula is only for demonstration purposes - the FFMI calculator does all the hard work for you.
FFMI Score Interpretation & Meaning
Your FFMI reading will have different meaning for men and women, depending on their gender.
Men
| FFMI Score | Interpretation |
|---|---|
| Under 18 | Below average muscularity |
| 18-20 | Average muscularity |
| 20-22 | Above average muscularity |
| 22-24 | Excellent muscularity |
| 24-26 | Elite natural muscularity |
| Over 26 | Steroid Use or exceptional genetics |
Women
| FFMI Score | Interpretation |
|---|---|
| Under 14 | Below average muscularity |
| 14-16 | Average muscularity |
| 16-18 | Above average muscularity |
| 18-20 | Excellent muscularity |
| Over 20 | Elite natural muscularity or Steroid Use |
FFMI vs BMI - Why FFMI is a Better Measure of Muscularity
FFMI vs BMI - the Body Mass Index is a poor indicator of muscularity as it does not differentiate between fat and muscle. This means that bodybuilders and other muscular individuals can be classified as overweight or obese by BMI, when they are, in fact, very lean. FFMI on the other hand measures fat-free mass, which is much more representative of someone's muscularity.
For example, let's say you're a 5'10 male, that weighs 200lbs at a body fat of 10%, and you're wondering how you compare with other bodybuilders. Well, your BMI would be 28.7, and based on this number, it would suggest that you're overweight. But based on your FFMI score, it would appear that you have an excellent muscularity, in comparison to the natural muscularity limit.
FFMI Natural Limit (What's the Maximum FFMI?)
As previously mentioned, the natural FFMI limit for men is approximately 25, and for women around 20. People have the occasional outlier, but anything above these numbers would usually suggest that an individual has been supplementing with anabolic steroids or a similar performance-enhancing drug.
It's also worth noting that the limits for FFMI are general guidelines only. A lot of people, even those with exceptional genetics, will struggle to achieve an FFMI above the average level, whilst others, with less than ideal genetics, might find that they have a FFMI that is above average.
How to Increase Your FFMI Score
Increasing your FFMI score comes down to increasing your fat-free mass. You can do this by following these tried and tested methods:
- Strength Training - Focus on compound lifts.
- Progressive Overload - Gradually increase the intensity of your workouts.
- Optimal Nutrition - Eat enough protein, and enough calories so that you are in a caloric surplus.
- Appropriate Recovery - Ensure you eat well, get enough sleep, and reduce your stress levels.
- Consistency - You won't see results if you don't stay consistent and commit to what you're doing.