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?

Measure waist circumference at the navel (belly button) level while standing relaxed — do not suck in. 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).

Body Fat Calculator

Name: Body Fat Calculator
Availability: InStock
Author: Nham Vu

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

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.

Height, weight, neck, and waist are required.

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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.

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.
Measure and enter your neck circumference and waist circumference at the navel.
If female, also enter your hip circumference at the widest point.
Choose a calculation method (Navy, Jackson-Pollock 3-site, or YMCA) from the selector.
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: 2026-06-09 · Reviewed by Nham Vu