FFMI Calculator

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.

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?

Choose between imperial (feet/inches, lbs) or metric (cm, kg). Input your height and weight. Input your current body fat percentage (approximate if unsure). 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.