What is the US Navy body fat method?

The Navy method was developed by Hodgdon and Beckett at the Naval Health Research Center in 1984. It estimates body fat from circumference measurements using a logarithmic formula validated against hydrostatic (underwater) weighing.

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).

Is my data sent to a server?

All calculations are pure JavaScript running in your browser. Our servers are not involved at any point.

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).

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, the hip measurement is added to the waist. All logarithm and arithmetic operations run locally in your browser using JavaScript. No data is sent to our servers.

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 height alone, try the BMI calculator. To work out fat-free mass from total weight, use the lean body mass calculator. For a healthy weight range based on your frame, see the ideal weight calculator.

Frequently asked questions

What is the US Navy body fat method?: The Navy method was developed by Hodgdon and Beckett at the Naval Health Research Center in 1984. It estimates body fat from circumference measurements using a logarithmic formula validated against hydrostatic (underwater) weighing.
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).
Is my data sent to a server?: All calculations are pure JavaScript running in your browser. Our servers are not involved at any point.

Last reviewed May 26, 2026