Body Fat Calculator
Calculate your body fat percentage using the US Navy method or BMI-based estimation. Get your fat mass, lean mass, and body composition category.
Body Composition
Body Fat
17.4%
Average
Basic Information
Measurements
At navel level
At narrowest point
Your Body Composition
Body Fat Categories (Men)
How to Measure
Waist
- Measure at navel level
- Stand relaxed, don't suck in
- Measure at end of normal exhale
Neck
- Measure at narrowest point
- Below the Adam's apple
- Keep tape level
Body Composition
Body Fat
17.4%
Average
Quick Answer: How to Calculate Body Fat
To calculate body fat percentage using the US Navy method: For men, measure waist at navel and neck at narrowest point, then use the formula: 86.010 x log10(waist - neck) - 70.041 x log10(height) + 36.76. For women, also measure hips at widest point. Healthy ranges are 10-20% for men (fit) and 18-28% for women (fit). The Navy method is accurate within 3-4% for most people.
Key Facts About Body Fat
- US Navy body fat formula is accurate within 3-4% for most individuals
- Healthy body fat: Men 10-20% (fit), 21-24% (average); Women 18-28% (fit), 29-31% (average)
- Essential fat minimum: Men 2-5%, Women 10-13% - required for basic body functions
- Athletic body fat: Men 6-13%, Women 14-20%
- Body fat percentage is a better health indicator than weight or BMI alone
- Measure waist at navel level, relaxed, at end of normal exhale
- Measure neck at narrowest point below Adams apple
- Women also measure hips at the widest point for accurate calculation
Related Health Calculators
Frequently Asked Questions
The US Navy body fat formula is generally accurate within 3-4% for most people. It uses waist and neck measurements (plus hips for women) to estimate body fat. While not as precise as DEXA scans or hydrostatic weighing, it provides a good estimate for tracking progress.
Healthy body fat ranges vary by gender. For men: 10-20% is fit, 21-24% is average. For women: 18-28% is fit, 29-31% is average. Athletes may be lower. Essential fat (minimum needed for health) is 2-5% for men and 10-13% for women.
Measure your waist at the narrowest point, typically at the navel or just above. Stand relaxed, don't suck in your stomach. Measure at the end of a normal exhale. The tape should be snug but not compressing the skin.
Body fat percentage is more indicative of health than weight alone. Two people at the same weight can have vastly different body compositions. High body fat increases risk of heart disease, diabetes, and other conditions, even at "normal" weight.
Measure every 2-4 weeks for tracking progress. Body fat changes slowly, so daily measurements aren't useful. Measure at the same time of day, under similar conditions (morning, fasted) for consistency.
Body Composition
Body Fat
17.4%
Average
Medical Disclaimer
This calculator is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider before making any health-related decisions.