Body Fat Calculator

A body fat calculator is an online tool that estimates your body fat percentage using body measurements such as height, weight, waist, neck, and hip circumferences. Whether you're tracking fitness progress, monitoring health metrics, or working with a trainer, our body fat calculator provides accurate estimates using scientifically validated methods like the US Navy formula.

This calculator determines not just your body fat percentage but also breaks down your total weight into fat mass and lean body mass (muscles, bones, organs, and water). The US Navy method uses circumference measurements combined with height and gender to estimate body composition without requiring expensive equipment like body scanners or calipers.

Accurate body composition assessment is more meaningful than weight alone for health and fitness tracking. Athletes and fitness enthusiasts use body fat calculators to monitor muscle gain and fat loss, as scale weight doesn't distinguish between fat and muscle. Someone can weigh the same but have completely different body compositions with different health implications.

Healthcare professionals and personal trainers use body fat percentage to assess health risks, as excess body fat, especially visceral fat, is linked to cardiovascular disease, diabetes, and metabolic syndrome. Dieters benefit from tracking body fat to ensure weight loss comes from fat rather than muscle, preserving metabolism and strength.

The tool ensures practical accuracy using validated formulas like the US Navy method, which has been tested across diverse populations. It provides instant results without expensive equipment, helps track meaningful fitness progress beyond scale weight, and gives insight into body composition changes. It's particularly valuable when combined with regular measurements to track trends over time.

Fitness Progress Tracking: Monitor body composition changes during weight loss or muscle-building programs to ensure you're losing fat while preserving or gaining muscle.

Health Risk Assessment: Evaluate health risks associated with body fat levels, as high body fat percentage correlates with increased cardiovascular and metabolic disease risk.

Athletic Performance: Athletes track body fat to optimize performance, maintain proper competition weight categories, and ensure adequate energy reserves.

Personal Training: Trainers use body fat measurements to create customized fitness and nutrition plans based on individual body composition goals.

Weight Management: Distinguish between fat loss and muscle loss during dieting to adjust nutrition and exercise strategies for better outcomes.

Using our body fat calculator is straightforward: enter your gender, height, weight, and body circumference measurements (waist, neck, and hips for women). The calculator uses these measurements with the US Navy formula to estimate your body fat percentage, fat mass, and lean body mass instantly.

The US Navy formula for men: Body Fat % = 86.010 × log10(abdomen - neck) - 70.041 × log10(height) + 36.76. For women: Body Fat % = 163.205 × log10(waist + hip - neck) - 97.684 × log10(height) - 78.387. Measurements should be taken consistently at the same time of day, at the same body locations, for accurate tracking. All calculations are performed locally in your browser for privacy. Healthy body fat ranges are typically 10-20% for men and 20-30% for women, though this varies by age and fitness level.