Results
Body Fat %: –
Fat Mass: –
Lean Mass: –
Classification: –
Age-Based Interpretation: –
Overview
Calculate your body fat % based on weight, waist, neck, and height using the U.S. Navy method. More reliable than BMI for fitness tracking.
This tool helps track body composition changes for health goals like fat loss or muscle gain.
Formula & Methodology
Men: \( BF\% = 86.010 \cdot \log_{10}(waist - neck) - 70.041 \cdot \log_{10}(height) + 36.76 \)
Women: \( BF\% = 163.205 \cdot \log_{10}(waist + hip - neck) - 97.684 \cdot \log_{10}(height) - 78.387 \)
Examples
- Male, 180 cm (70.9 in), 90 cm (35.4 in) waist, 40 cm (15.7 in) neck, 80 kg (176 lbs) → ~20% body fat
- Female, 165 cm (65 in), 75 cm (29.5 in) waist, 95 cm (37.4 in) hip, 35 cm (13.7 in) neck, 70 kg (154 lbs) → ~28%
Use Cases
- Track fitness progress
- Estimate body composition for meal planning
- Use for gym routines, coaching, or weight loss goals
- Monitor health and wellness targets
- Support meal planning or body recomposition goals
Body Fat Ranges
Men:
- Essential fat: 2–5%
- Athletes: 6–13%
- Fitness: 14–17%
- Average: 18–24%
- Obese: 25%+
Women:
- Essential fat: 10–13%
- Athletes: 14–20%
- Fitness: 21–24%
- Average: 25–31%
- Obese: 32%+
FAQ
Why is weight required?
Weight allows us to convert body fat % into actual fat and lean mass in pounds or kilograms, which is more useful for health planning.
Why is hip measurement only for women?
The formula accounts for different fat distribution patterns by gender, including hips for women.
What is a healthy body fat for my age?
This tool includes age-based classifications to show if your percentage falls in a healthy range for your gender and age group.