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WEIGHT & BODY · CIRCUMFERENCE METHOD

Body Fat Estimate Calculator

Estimate body fat percentage from height and body circumferences using a documented sex-specific circumference equation.

Method: circumference-based body-fat equation; informational estimate onlyLast updated:
YOUR DETAILS

Your body measurements

Choose your units and enter the tape measurements below.

Body fat estimate inputs
Measurement units

Your entries are calculated in your browser by this tool and are not intentionally stored or sent by the calculator code.

Method used

This tool uses sex-specific circumference equations historically used in U.S. military body-composition assessment. It is provided as a general estimate, not as a current military eligibility test or clinical measurement.

Equation and units

All measurements are converted to inches before applying the historical circumference equations:

Male estimate (%) = 86.010 × log10(abdomen − neck) − 70.041 × log10(height) + 36.76

Female estimate (%) = 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387

log10 means the base-10 logarithm. This tool retains precision during the calculation and rounds only the final percentage. It does not reproduce administrative tape-measure rounding rules.

Measurement matters

Use a non-stretch tape, held snugly without compressing the skin. Measure height without shoes and neck just below the larynx. The male equation uses abdomen circumference at the navel; the female equation uses the natural waist and the widest hip circumference. Tape placement and body shape can materially change the estimate. This tool is for adults, not children or pregnancy.

Important 2026 context

Military body-composition policies change over time. For example, the U.S. Army adopted waist-to-height ratio in 2026 and rescinded previous Army body-fat assessment methods. This calculator should therefore be treated as an informational body-fat estimate, not a current Army standard.

References & sources

  1. U.S. Army historical circumference body-fat calculation reference.
  2. U.S. Army 2026 body-composition update adopting waist-to-height ratio.
  3. Health.mil: Body Composition Testing.

Sources checked and page updated on . This tool is for general educational use and is not a diagnosis or personal medical prescription.