FFMI Calculator

Use the FFMI Calculator for a transparent, instant calculation with validated inputs and cited sources. For a query such as “ffmi calculator”, enter the matching values and units below and review the stated assumptions.

Inputs

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Result

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Fat-free mass index
20.987654321
Kouri height-normalized FFMI
20.987654321

How to use this calculator

Enter the requested values and units.

Review the assumptions and any warnings shown with the result.

Use the result together with the cited source and your real-world requirements.

Formula

FFMI = fat-free mass in kilograms ÷ height in meters².

Worked example

Worked example: Inputs: Body weight: 80 kg; Body fat percentage: 15 %; Height: 1.8 m. Outputs: Fat-free mass index: 20.987654; Kouri height-normalized FFMI: 20.987654.

Assumptions and limits

  • The result depends on the values, units, and assumptions entered. It does not infer missing context.
  • Review the assumptions and any warnings shown with the result.

Sources

Related calculators

Frequently asked questions

How does the FFMI Calculator work?

FFMI = fat-free mass in kilograms ÷ height in meters².

What should I enter?

Body weight, Body fat percentage, Height

What should I verify?

Review the assumptions and any warnings shown with the result. The result depends on the values, units, and assumptions entered. It does not infer missing context.

Last updated 2026-08-14 · health-ffmi-v1 · opportunity-content-2026-08-14 · Trusty Calculator Editorial Team