What this calculator tells you
The circumference method turns a small set of tape measurements into a rough body-fat estimate. Its convenience makes it useful for tracking trends when measurements are taken consistently.
How to use the Body Fat Calculator
- 1
Use a flexible tape and choose centimetres or inches.
- 2
Measure height, neck, waist, and hips where requested.
- 3
Repeat measurements and use the result as an estimate.
Formula and interpretation
Method
The Navy circumference equations use logarithms of height and sex-specific combinations of neck, waist, and hip measurements.
How to read the result
Track the direction of change under the same conditions. A single result is less useful than several careful measurements taken over time.
Important limitations
Tape placement and body shape can materially change the estimate. This is not equivalent to DEXA, hydrostatic weighing, or a clinical assessment.
Body Fat Calculator questions
Where should I measure my waist?
Follow the method shown by the source standard and keep the tape level. Consistency matters more than pulling the tape tight.
Can I compare this with a smart scale?
You can compare trends, but different methods use different assumptions and may not agree on the absolute percentage.
