Estimate your body fat percentage using the US Navy Circumference Method. Get lean mass vs fat mass breakdown, category analysis, and personalized macronutrient targets.
Our body fat calculator online estimates your body fat percentage using the US Navy Circumference Method — one of the most accurate techniques that doesn't require specialized equipment. By measuring just a few body circumferences, you can get a reliable body composition estimate.
Understanding your body fat percentage is more important than just tracking weight, as this body fat calculator online distinguishes between fat mass and lean mass and provides personalized macronutrient targets.
Body fat percentage is a better health indicator than BMI for athletes and active individuals. Fitness enthusiasts can track muscle gain vs fat loss. Weight loss seekers can monitor true progress beyond the scale. Athletes can optimize body composition for performance.
Fitness Tracking: Monitor muscle gain and fat loss over time.
Nutrition Planning: Get personalized macronutrient targets.
Health Screenings: Assess body composition for wellness programs.
TooliFyra's body fat calculator online is 100% private — all calculations happen in your browser and no data is ever sent to a server. It's completely free with no sign-up required.
The US Navy Method has an accuracy of ±3% compared to DEXA scans when measurements are taken correctly, making it one of the most accurate circumference-based methods.
For men: 10-20% is fit, 6-13% is athletic. For women: 18-28% is fit, 14-20% is athletic. Essential fat is 2-5% for men and 10-13% for women.
Absolutely. All calculations happen locally in your browser. Your body measurements never leave your device.