Body Fat Calculator
Calculate body fat percentage using multiple proven methods including Navy, Army, and Covert Bailey formulas with detailed body composition analysis. Perfect for fitness tracking and health assessment with accurate measurements.
Continue Your Calculators Journey
What is Body Fat Calculator?
Enter your gender, height, and body measurements to estimate your body fat percentage. The calculator supports the Navy method, which uses neck and waist circumference (and hip for women), and the BMI-based estimation method. Results include your body fat percentage, fat mass, lean mass, and category classification (essential, athlete, fitness, acceptable, obese).
How does Body Fat Calculator work?
The Navy method estimates body fat using circumference measurements and the US Navy formula. For men: BF% = 86.010 * log10(waist - neck) - 70.041 * log10(height) + 36.76. For women: BF% = 163.205 * log10(waist + hip - neck) - 97.684 * log10(height) - 78.387. The BMI method uses: BF% = (1.20 * BMI) + (0.23 * age) - 16.2 for men and (1.20 * BMI) + (0.23 * age) - 5.4 for women.
Key Features
- Supports Navy method and BMI-based estimation
- Separate calculations for men and women
- Shows fat mass and lean body mass breakdown
- Category classification based on essential fat ranges
- Accepts metric and imperial measurements
- No data stored or transmitted
Common Use Cases
Fitness progress tracking
Monitor body fat changes over weeks or months as part of a training or diet program.
Goal setting
Set realistic body composition targets based on your current measurements and fitness category.
Pre-competition prep
Athletes in bodybuilding, wrestling, or military can estimate their body fat for category compliance.
Health assessment
Use body fat percentage alongside BMI for a more complete picture of body composition.
How to Use This Tool
Select your gender and method
Choose male or female, and pick between the Navy method or BMI-based method.
Enter your measurements
For the Navy method, input height, neck circumference, waist circumference, and hip circumference (women only). For BMI method, input height, weight, and age.
Review your results
See your estimated body fat percentage, fat mass, lean mass, and fitness category.
Pro Tips
- 1
Take measurements in the morning before eating for the most consistent results
- 2
Use a flexible tape measure and keep it snug but not compressing the skin
- 3
Measure your waist at the narrowest point, typically at or above the navel
- 4
For the most accurate results, average three measurements taken on the same day
Frequently Asked Questions
How accurate is the Navy method?
The Navy method is generally within 3 to 4 percent of hydrostatic weighing for most people. It is more accurate than BMI-based methods but less accurate than DEXA scans or Bod Pod measurements.
What is the difference between the Navy method and BMI method?
The Navy method uses circumference measurements of the waist, neck, and hips to estimate body fat directly. The BMI method estimates body fat indirectly from BMI and age, which is less precise but requires fewer measurements.
What body fat percentage is healthy?
For men, essential fat is 2 to 5 percent, athletes are 6 to 13 percent, fitness is 14 to 17 percent, and acceptable is 18 to 24 percent. For women, essential fat is 10 to 13 percent, athletes are 14 to 20 percent, fitness is 21 to 24 percent, and acceptable is 25 to 31 percent.
Why do women need hip measurements?
Women store more fat around the hips and thighs. The Navy formula for women includes hip circumference to account for this difference in fat distribution and produce a more accurate estimate.
Can I use this calculator if I am very muscular?
The Navy method works reasonably well for muscular individuals because it uses circumferences rather than weight. However, extremely muscular people may still get a slightly elevated reading due to larger neck and waist measurements.