Body Fat Estimate
Estimate body-fat percentage with the U.S. Navy circumference equations using height, neck, waist, and reference sex.
How to use
- Choose reference sex and enter height, neck, and waist circumference.
- For the female equation also enter hip circumference, then calculate.
Capabilities and scope
The male equation uses waist−neck; the female equation uses waist+hip−neck, with measurements entered in centimetres.
How it works
The male implementation is 495/(1.0324−0.19077log10(waist−neck)+0.15456log10(height))−450; the female mode uses its corresponding hip-inclusive equation.
Example
Changing tape placement or breathing can change the estimate even for the same person.
Interpretation
The runner rejects combinations producing values below 0% or above 75%.
Useful for
- Track a circumference-based estimate consistently over time
- Inspect a formula result when direct composition measurement is unavailable
Before you use it
- It is sensitive to measurement technique and is not a clinical body-composition assessment or diagnosis.
Edge cases
- Waist must exceed neck; female mode also requires a positive hip circumference.
Standards and references
Frequently asked questions
Why do small tape-measure differences matter?
The equations use logarithms of circumference combinations, so measurement differences propagate into the estimate.