Body Fat Calculator
Estimate your body fat percentage using the US Navy Circumference Method with neck, waist, and hip measurements.
Enter Your Parameters
Understanding Your Result
The calculation generated by this tool provides an evidence-based assessment derived from established physiological and clinical equations. Use this measurement as an educational indicator alongside broader lifestyle variables, including overall dietary quality, resistance training, cardiovascular endurance, and routine medical checkups.
Mathematical Formula & Scientific Methodology
The US Navy method uses logarithmic equations based on circumference measurements. For Men: %BF = 495 / (1.0324 - 0.19077 × log10(waist - neck) + 0.15456 × log10(height)) - 450. For Women: %BF = 495 / (1.29579 - 0.35004 × log10(waist + hip - neck) + 0.22100 × log10(height)) - 450.
Step-by-Step Example Calculation
Clinical Limitations & Nuances
Tape measurement precision depends on exact landmarking and tension. It typically correlates within 3-4% of DEXA scans but can vary with water retention.
Frequently Asked Questions
What is considered an essential body fat percentage?
Essential fat is required for physiological health: 2-5% for men and 10-13% for women. Dropping below these thresholds poses significant hormonal risks.
How often should I measure my body fat?
Measuring every 2 to 4 weeks at the same time of day (ideally in the morning before eating) provides the most reliable trend tracking.
Dr. Sarah Mitchell, MS, RD
Exercise Physiologist & Clinical Dietitian
Formulas and educational copy on Body Metric Hub are researched and verified by certified clinical nutritionists and exercise physiology specialists.