Where do I measure my neck for the Navy method?

Measure just below the larynx (Adam's apple), keeping the tape snug without compressing the skin and angled slightly downward toward the front of the neck. Take the reading two or three times and use the average.

How does the Navy method compare to other methods?

It is comparable in accuracy to skinfold calipers (both ±3–4%) and more practical than DEXA or hydrostatic weighing. It is less accurate for very muscular or very lean individuals.

What are the US Navy body fat standards?

The US Navy maximum body fat standards are graduated by age. For men they are 22% (ages 18–21), 23% (22–29), 24% (30–39), and 26% (40 and over). For women they are 33% (18–21), 34% (22–29), 35% (30–39), and 36% (40 and over).

Does the calculator work offline?

Once the page has loaded, yes. The formula runs in the open tab, so it keeps working if your connection drops. Reloading or opening another page needs a connection again.

Navy body fat calculator

The US Navy body fat calculator uses circumference measurements to estimate body fat percentage, the same method used by the US military for fitness assessments. Choose your sex and enter your measurements to get an instant estimate.

Sex

Units

Neck (cm)

Waist (cm)

Height (cm)

Measure neck below larynx, waist at narrowest point (usually above navel).

Results are for informational purposes and do not constitute medical advice.

How it works

The US Navy circumference method uses a logarithmic formula to estimate body fat from tape measurements. For men: BF% = 495 / (1.0324 − 0.19077 × log₁₀(waist − neck) + 0.15456 × log₁₀(height)) − 450. For women: BF% = 495 / (1.29579 − 0.35004 × log₁₀(waist + hip − neck) + 0.22100 × log₁₀(height)) − 450. All measurements are in cm; inch inputs are multiplied by 2.54 first. All logarithm and arithmetic operations run locally in your browser using JavaScript.

Processing runs in your browser

The entire calculation runs in the browser page using pure JavaScript. Our servers are not involved at any point.

Technical specification

The US Navy circumference method was developed by Hodgdon and Beckett at the Naval Health Research Center (1984) and validated against hydrostatic (underwater) weighing. The formula uses circumference measurements and the logarithm of measurement differences. Accuracy is ±3–4 percentage points, similar to skinfold caliper methods. DEXA scanning remains the gold standard for body composition measurement.

Method: US Navy circumference method (Hodgdon & Beckett, 1984)
Accuracy: ±3–4 percentage points
Men inputs: Neck, waist, height
Women inputs: Neck, waist, hip, height

Related operations

For a general weight category from your height and weight, try the BMI calculator. To split total weight into estimated lean and fat mass, use the lean body mass calculator. For a reference weight range for your height, see the ideal weight calculator.

Frequently asked questions

Where do I measure my neck for the Navy method?: Measure just below the larynx (Adam's apple), keeping the tape snug without compressing the skin and angled slightly downward toward the front of the neck. Take the reading two or three times and use the average.
How does the Navy method compare to other methods?: It is comparable in accuracy to skinfold calipers (both ±3–4%) and more practical than DEXA or hydrostatic weighing. It is less accurate for very muscular or very lean individuals.
What are the US Navy body fat standards?: The US Navy maximum body fat standards are graduated by age. For men they are 22% (ages 18–21), 23% (22–29), 24% (30–39), and 26% (40 and over). For women they are 33% (18–21), 34% (22–29), 35% (30–39), and 36% (40 and over).
Does the calculator work offline?: Once the page has loaded, yes. The formula runs in the open tab, so it keeps working if your connection drops. Reloading or opening another page needs a connection again.

Last reviewed September 30, 2026

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