Calculate your Fat Free Mass Index

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66 lbs 396 lbs
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Fat Free Mass

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FFMI

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Normalized FFMI

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Category: --

16
17
18
19
20
22
24
26
28+
Below Average (16-17)

Indicates lower muscle mass than average. Common in beginners or those new to resistance training.

Average (18-19)

Typical range for healthy adults with moderate physical activity but no specific muscle training.

Above Average (20-21)

Indicates regular resistance training and good muscle development. Common among fitness enthusiasts.

Excellent (22-23)

Shows dedicated training and nutrition. Typical for experienced weightlifters and athletes.

Superior (24-25)

Advanced level of muscle development. Common among competitive athletes and bodybuilders.

Exceptional (26-27)

Very high level of muscle mass. Typically seen in elite athletes and professional bodybuilders.

Elite (28+)

Extremely rare level of muscle mass. Reaching this level naturally is exceptionally difficult and uncommon.

What Is FFMI?

FFMI (Fat-Free Mass Index) measures the amount of lean muscle mass you have in relation to your height. It’s more bodybuilding-oriented than BMI, helping you understand your muscle-to-height ratio. It was developed as an alternative to BMI specifically for athletes and bodybuilders.

How Is FFMI Calculated?

The formula for FFMI is based on your fat-free mass (FFM) divided by your height in meters squared:

FFM = Weight - (Weight * BodyFat%)
FFMI = (FFM / 2.2) / (Height in meters)²
Adjusted FFMI = FFMI + (6.3 * (1.8 - Height in meters))

Don’t worry about memorizing these formulas — the calculator above handles it for you automatically.

FFMI and Body Fat Ranges

Use this table as a guide. Real-world results vary by genetics, nutrition, and training history. Body fat ranges may overlap, so these are rough categories, not strict rules.

For Men

FFMI Range Typical Body Fat Description
Below 16 20% or higher Indicates low muscle mass, often found in beginners or those who do not lift weights.
16–17 15–20% Slightly below average muscle. May be seen in casual or infrequent exercisers.
18–19 12–16% Average. Suggests moderate muscle but not extensive training.
20–21 10–15% Indicates regular training and decent muscle development. Often seen in consistent gym-goers.
22–23 8–12% Advanced development with structured workouts and strong diet habits.
24–25 8–20% Very high muscle mass. Common in competitive athletes and experienced lifters.
26–27 8–15% Rare natural level. Usually gained through many years of focused training.
28+ Varies widely Extremely advanced or “elite.” May reflect genetics, special coaching, or very long-term training.

For Women

FFMI Range Typical Body Fat Description
Below 14 25% or higher Suggests low muscle mass relative to height. Common in those new to strength training.
14–15 20–25% Slightly below average muscle. Often seen in casual exercisers or beginners.
16–17 18–25% Moderate muscle development. Typical for steady gym-goers.
18–19 15–22% Shows dedicated training. Common in athletes or committed fitness enthusiasts.
20–21 15–30% Advanced level. Often found in competitive sports or well-structured strength programs.
22–23 15–25% Elite muscle development. Requires long-term commitment and specialized training.
24–25 15–25% Very rare naturally. Typically gained through years of intense workout routines and strict nutrition.
26+ Varies widely Exceptional or elite range. May reflect unique genetics or very advanced fitness methods.

What Do My Results Mean?

Depending on your FFMI score, you can categorize yourself along a scale from “Below Average” to “Elite” (which might hint at extremely high or unnatural muscle mass). Most recreational lifters will land in the “Average” to “Excellent” range.

How Do I Use This Calculator?

  1. Choose between imperial (feet/inches, lbs) or metric (cm, kg).
  2. Input your height and weight.
  3. Input your current body fat percentage (approximate if unsure).
  4. Observe your FFMI, normalized FFMI, and other results.

What Else Should I Consider?

  • Gender Differences: Men and women tend to have different body fat distributions and muscle mass potential.
  • Training History: If you’re new to training, your FFMI may rise quickly, then taper.
  • Lifestyle Factors: Nutrition, rest, and workout consistency impact your FFMI significantly.