Body Fat Calculator
Estimate your body fat percentage using the Navy method
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Understanding Body Fat Percentage
Our body fat calculator estimates your body fat percentage using the U.S. Navy circumference method. Understand your body composition beyond just weight, and learn what body fat levels mean for health and fitness.
What is Body Fat Percentage?
Body fat percentage is the proportion of your total body weight that is fat. Unlike BMI, it distinguishes between fat mass and lean mass (muscle, bone, organs). Lower body fat isn't always better-some fat is essential for health.
Navy Method Calculation
Men: %BF = 495/(1.0324 - 0.19077×log10(waist-neck) + 0.15456×log10(height)) - 450. Women: %BF = 495/(1.29579 - 0.35004×log10(waist+hip-neck) + 0.22100×log10(height)) - 450.
Example:
For a man with 34" waist, 15" neck, 70" height: %BF = 495/(1.0324 - 0.19077×log10(19) + 0.15456×log10(70)) - 450 ≈ 18%.
Common Use Cases
Real-world applications for this calculator
Fitness Assessment
Track body composition changes during a fitness program-even when the scale doesn't move.
Health Evaluation
Assess health risks associated with body fat levels, particularly visceral fat.
Goal Setting
Set realistic body fat goals based on health guidelines and athletic aspirations.
Tips
- Measure in the morning, before eating, for consistency.
- Body fat percentage is more meaningful than just scale weight.
- Extremely low body fat (<5% men, <12% women) is unhealthy.
- Building muscle can improve body composition without weight change.
Frequently Asked Questions
What is a healthy body fat percentage?
For men: essential fat is 2-5%, athletes 6-13%, fitness 14-17%, acceptable 18-24%, obesity 25%+. For women: essential fat is 10-13%, athletes 14-20%, fitness 21-24%, acceptable 25-31%, obesity 32%+.
How accurate is the Navy method?
The Navy method is typically accurate within 3-4% of actual body fat. It's more accurate than BMI but less precise than methods like DEXA scans or hydrostatic weighing.
Why do women have higher body fat percentages?
Women naturally carry more essential fat for reproductive functions and hormonal health. A fit woman at 20% body fat is comparable to a fit man at 10-12% in terms of leanness.
Can I be skinny fat?
Yes, "skinny fat" describes someone with normal weight but high body fat and low muscle mass. BMI may be normal while body fat percentage is high. Strength training helps improve body composition.
What is essential vs storage fat?
Essential fat is needed for normal body function (3% men, 12% women minimum). Storage fat is energy reserves under skin and around organs. Too little essential fat causes health problems; too much storage fat increases health risks.