How accurate is the US Navy method?

The US Navy method is reasonably accurate (within 3-4% of DEXA scans) for most people. It may be less accurate for very lean or very obese individuals.

How to measure waist and neck correctly?

Measure your waist at the narrowest point (usually at the navel). Measure your neck just below the larynx (Adam's apple). Keep the tape level and snug but not tight.

Body Fat Calculator

Estimate your body fat percentage using the US Navy method with simple body measurements.

Gender

Height (cm)

Weight (kg)

Waist (cm) — at navel

Neck (cm)

What is Body Fat Percentage?

Body fat percentage is the total mass of fat divided by total body mass, expressed as a percentage. It's a more accurate indicator of fitness than weight alone, as it accounts for muscle mass, bone density, and body composition.

US Navy Body Fat Formula

Males: BF% = 495 / (1.0324 – 0.19077 × log10(W–N) + 0.15456 × log10(H)) – 450

W = Waist · N = Neck · H = Height (all in cm)

Females: BF% = 495 / (1.29579 – 0.35004 × log10(W+Hip–N) + 0.22100 × log10(H)) – 450

W = Waist · Hip = Hip circumference · N = Neck · H = Height (all in cm)

Body Fat Categories

Essential Fat: Men 2-5% · Women 10-13%
Athletes: Men 6-13% · Women 14-20%
Fitness: Men 14-17% · Women 21-24%
Average: Men 18-24% · Women 25-31%
Obese: Men 25%+ · Women 32%+

Frequently Asked Questions

The US Navy method is accurate within 3-4% for most people. While not as precise as DEXA scans or hydrostatic weighing, it's a practical and free estimation method that only requires a tape measure.

BMI only considers height and weight, so muscular individuals may be classified as overweight. Body fat percentage directly measures fat vs lean mass, providing a more accurate picture of body composition and health.

Waist: Measure at the navel level, relaxed, without sucking in. Neck: Measure below the larynx (Adam's apple), tape sloping slightly downward. Hip (women): Measure at the widest point. Always use inches or centimeters consistently.