Body Fat Calculator

Estimate body-fat percentage with a legacy circumference equation historically used by the U.S. Navy. Results are tape-measure estimates, not a diagnosis or the current Navy assessment standard.

How to measure: Use a flexible tape. Neck — just below the larynx. Waist — narrowest point (women) or navel (men). Hips (women) — widest point.

Height (cm)

Neck (cm)

Waist (cm)

Hips (cm) female equation only

About This Tool

What it does

Uses a legacy sex-specific tape-measure equation based on height and neck, waist and (for the female equation) hip circumferences. It does not implement the current U.S. Navy height-waist-weight table procedure.

Who it's for

Adults who want a repeatable home trend estimate. Results can differ from DEXA, bioimpedance, skinfolds and current military standards and should not be used for diagnosis.

Your privacy

All calculations happen in your browser. No data is transmitted or stored anywhere.

What this estimate represents

This calculator implements the older circumference equations commonly described as the U.S. Navy tape method. The current U.S. Navy Physical Readiness Program uses a different height-waist-weight table procedure, so this result must not be presented as a current Navy compliance result.

Small changes in tape position or tension can materially change the estimate. Compare trends only when the same method and measurement technique are used.

Authoritative references

Reviewed 23 June 2026: U.S. Navy Physical Readiness Program guides; US CDC: limits of body-composition screening measures.

Helpful guides

Body fat percentage vs BMICompare the two measures, their strengths and their limitations.Read guide →

Frequently Asked Questions

Which body-fat method does this calculator use?

It uses older sex-specific circumference equations based on height and tape measurements. These equations are often called the legacy U.S. Navy tape method.

Is this the current U.S. Navy body-composition test?

No. Current Navy guidance uses a different height-waist-weight table procedure. This calculator is retained as a general legacy tape-measure estimate only.

Why does measurement technique matter?

Tape position, tension, breathing and rounding affect the circumferences and can materially change the estimated percentage. Measure consistently and treat small changes cautiously.

Does the result diagnose a healthy or unhealthy body-fat level?

No. There is no single calculator cut-off that diagnoses individual health. Age, sex, body composition, medical history and measurement method all matter.