What is the U.S. Navy body fat method?

The U.S. Navy method estimates body fat percentage from circumference measurements — neck, waist, and (for women) hips — along with height. It uses a logarithmic formula derived from studies on military personnel and is widely used because it requires only a tape measure.

How accurate is the body fat calculator?

Circumference-based methods like the Navy formula have a typical error margin of ±3–4 percentage points. Accuracy depends on consistent measurement technique. For clinical precision, use DEXA scan, hydrostatic weighing, or Bod Pod testing.

What body fat percentage is considered healthy?

Healthy ranges differ by sex. For men, 6–17% is considered Athlete to Fitness, and 18–24% is Average. For women, 14–24% is Athlete to Fitness, and 25–31% is Average. Above these ranges is generally considered Obese by fitness standards.

Where should I measure waist and hip circumference?

Stand relaxed and do not suck in. Men measure the waist at the navel (belly button); in the Navy procedure, women measure it at the narrowest point of the waist. For hip circumference (women only), measure at the widest point of the hips and buttocks. Neck circumference is measured just below the larynx (Adam's apple).

What is the Navy body fat formula?

With all measurements in inches, men: body fat % = 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76. Women: 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387. The equations come from Hodgdon and Beckett at the Naval Health Research Center (1984).

Is body fat percentage better than BMI?

It answers a different question. BMI uses only height and weight, so a muscular person can rate as overweight. Body fat percentage estimates how much of your weight is fat, which says more about body composition. Doctors still use BMI for screening because it is quick and consistent.

Body Fat Calculator

Enter your sex, age, weight, height, and body measurements to estimate body fat percentage, fat mass, lean body mass, and your body fat category.

The US Navy method needs only a tape measure: men use waist minus neck, women use waist plus hip minus neck, together with height.

Body Measurements

Units

Sex

Male Female

Age

Weight (kg)

Height (cm)

Neck (cm)

Waist (cm) (at navel)

Hip (cm) (widest point)

Calculation Method

Results

Real-time calculation

Enter your measurements to see results instantly.

Complete the measurements required by your selected method.

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Body Fat %

Fat Mass

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Lean Body Mass

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Body Fat Category Chart

Male Thresholds

Essential

2–5%

Athletes

6–13%

Fitness

14–17%

Average

18–24%

Obese

25%+

Your result

Method: U.S. Navy

Disclaimer: For informational purposes only. Body fat estimates have a ±3–4% error margin. Consult a healthcare professional for medical use.

Quick answer

The US Navy method needs only a tape measure: men use waist minus neck, women use waist plus hip minus neck, together with height. A man 5 ft 10 in with a 33 in waist and 15 in neck comes out at 15.5% body fat. Categories follow the American Council on Exercise chart.

Examples

Person	Measurements (in)	Body fat	Category
Man, 5 ft 10 in	Waist 33, neck 15	15.5%	Fitness
Man, 5 ft 10 in	Waist 38, neck 16	23.0%	Average
Woman, 5 ft 5 in	Waist 27, hip 35, neck 13	20.4%	Fitness
Woman, 5 ft 6 in	Waist 29, hip 38, neck 13.5	25.9%	Average

Enter your measurements.

Summary

Enter your sex, age, weight, height, and body measurements to estimate body fat percentage, fat mass, lean body mass, and your body fat category.

How it works

Select your unit system (Metric or Imperial) and your sex (Male or Female).
Enter your age, weight, and height in the provided fields.
For the Navy method, enter neck and waist circumference; women also enter hip circumference.
For Jackson-Pollock, enter age and the three skinfolds shown for your sex in millimeters.
Choose Navy, Jackson-Pollock 3-site, or YMCA; the calculator will require only that method's measurements.
Results — body fat percentage, fat mass, lean body mass, and category — update instantly.

Use cases

Track changes in body composition during a weight-loss or muscle-building program.
Determine whether current fitness level falls in the Athlete or Fitness category.
Compare body fat estimates from multiple formulas for a more complete picture.

Frequently Asked Questions

Last updated: 2026-05-23 · Reviewed by Nham Vu