📉Body Fat Calculator

Body Fat Calculator using the US Navy Method

Our free body fat calculator uses the method developed by the United States Navy (US Navy Body Fat Method). Simply measure your neck, waist and — for women — hip circumference with a tape measure. Once you enter the values, the calculator instantly computes your body fat percentage and assigns it to one of five categories: essential, athlete, fitness, acceptable, or obese. No scale or expensive equipment required.

What do the results mean and how should you interpret them?

Body fat percentage is the ratio of fat mass to total body mass. Unlike BMI, which cannot distinguish muscle from fat, body fat percentage gives a better picture of body composition. The athlete category (6–13% for men, 14–20% for women) indicates a low fat level typical of active amateurs and professional athletes. The fitness category (14–17% / 21–24%) corresponds to a healthy, athletic physique. Results above 25% for men and 32% for women indicate obesity, which increases the risk of cardiovascular and metabolic diseases.

Frequently asked questions

What is the US Navy method?

The US Navy method estimates body fat percentage from body circumferences (neck, waist, hips) and height. It is based on logarithmic formulas developed by the United States Navy and requires no expensive equipment — just a tailor's tape measure.

How do I measure body circumferences correctly?

Measure the neck horizontally at the narrowest point (below the larynx). Measure the waist horizontally at the narrowest point (usually at or just above the navel). Women also measure hips at the widest point of the buttocks. Take measurements in the morning, fasting, with muscles relaxed and breathing normally.

What is a healthy body fat level?

Healthy body fat levels vary by sex and age. For men the `fitness` range is 14–17% and acceptable is 18–24%. For women the `fitness` range is 21–24% and acceptable is 25–31%. The essential level (below 6% for men, below 14% for women) is safe only short-term for athletes.

How accurate is the calculator?

The US Navy method is accurate to within ±3–4 percentage points compared to precise measurements (DEXA, air displacement plethysmography). Results are influenced by body proportions and fat distribution. The calculator is a guide — more accurate measurement is provided by DEXA densitometry or multi-segment bioimpedance.