Fat Free Mass Index (FFMI) Calculator

How to calculate FFMI calculator?

FFMI quantifies fat-free mass relative to height to assess muscularity independent of body fat.

Use the formula: FFMI = (fat-free mass in kg) / (height in m)^2

Using the FFMI calculator calculator: an example

Example values: weight 80 kg, body fat 15%, height 180 cm.

Step-by-step calculation:

• Calculate fat-free mass: 80 kg × (1 − 0.15) = 68.0 kg.
• Convert height: 180 cm = 1.80 m.
• Compute FFMI: 68.0 ÷ (1.80)^2 ≈ 21.0.
• Interpret: compare to reference ranges; normalized FFMI adjusts for height differences when needed.

Frequently Asked Questions

What is a typical FFMI range?

Common natural male ranges are roughly 16–21; values above that are less common and may indicate exceptional muscularity.

What does normalized FFMI mean?

Normalized FFMI adjusts FFMI to a standard height (often 1.80 m) so individuals of different heights can be compared fairly.

How accurate is the FFMI calculation?

FFMI accuracy depends on the precision of body fat measurement; more accurate body fat methods yield more reliable FFMI results.