Calculate body fat % using the U.S. Navy method. Just 3 measurements.
This body fat calculator uses the U.S. Navy circumference method, considered one of the most reliable tape-measure-based methods available. Men need neck and waist measurements; women additionally need hip measurements. The calculator shows your body fat percentage, fat mass in kg, lean mass, BMI, and fitness category (essential fat, athlete, fitness, average, or obese). Perfect for fitness tracking, military fitness tests, personal training clients, and anyone monitoring their body composition without expensive equipment. All calculations run in your browser — no data is uploaded or stored anywhere. The calculator also displays your lean body mass and fitness category, helping you understand where you stand relative to essential, athletic, and average body fat ranges for your gender.