What is the US Navy body fat method?

The US Navy circumference method estimates body fat percentage from simple tape measurements. For men it uses height, neck, and waist; for women it adds hips. The formulas were developed by Hodgdon and Beckett (1984) and are used by all US military branches.

How accurate is this method?

The Navy method has an accuracy of approximately ±3–4% body fat when measurements are taken correctly. It is less accurate than DEXA scanning or hydrostatic weighing, but far more practical and free. Consistency in measurement technique matters most.

Where exactly do I measure waist and neck?

Neck: measure just below the larynx (Adam's apple), sloping slightly downward at the front. Waist (men): measure at the narrowest point, usually at the navel level. Waist (women): measure at the narrowest point of the abdomen. Hips (women): measure at the widest point of the hips/buttocks.

What are healthy body fat percentage ranges?

ACE guidelines — Men: Essential fat 2–5%, Athletes 6–13%, Fitness 14–17%, Acceptable 18–24%, Obese 25%+. Women: Essential fat 10–13%, Athletes 14–20%, Fitness 21–24%, Acceptable 25–31%, Obese 32%+.

What are US military body fat standards?

Maximum allowed body fat (age 17–20): Army men 20%, Army women 30%; Navy/Marines men 22%, women 33%. Standards become slightly more lenient in older age groups. This tool shows your result so you can compare against official tables.

Can I use this for children or teenagers?

The Navy method formulas were validated for adults. For people under 18, consult a healthcare provider for age-appropriate body composition assessment.

Navy Body Fat Calculator

Calculate your body fat percentage using the official US Navy tape-measure method. Supports both metric and imperial units for men and women.

Measurements

Sex

Units

Height (inches)

Neck circumference (inches)

Waist circumference (inches)

Enter your measurements and click Calculate

Summary

Calculate your body fat percentage using the official US Navy tape-measure method. Supports both metric and imperial units for men and women.

How it works

Select your sex (male or female).
Choose metric (cm) or imperial (inches) units.
Enter your height, neck circumference, and waist circumference.
Women: also enter your hip circumference.
Your estimated body fat percentage and fitness category appear instantly.

Use cases

Estimate body fat without expensive equipment or calipers.
Track body composition changes over weeks or months.
Check whether you meet US military body fat standards.
Compare your result against ACE fitness category ranges.
Use alongside BMI for a more complete picture of body composition.

Frequently Asked Questions

Last updated: 2026-09-20 · Reviewed by Nham Vu