Body Fat Percentage Calculator
Estimate your body fat percentage using the proven U.S. Navy circumference method. Just take a few simple measurements with a tape measure — no special equipment needed.
Body Fat Calculator
Get Your Results Emailed
Enter your email and we'll send you a summary of your body fat calculator calculation. No spam, unsubscribe anytime.
About the Body Fat Calculator
Body fat percentage provides a more accurate picture of body composition than BMI alone. This calculator uses the US Navy circumference method — a validated technique used by the US military — which estimates body fat using simple tape measurements.
Quick Start Guide
- Enter your values — Fill in the fields with numbers relevant to your body fat calculation. Most fields include sensible defaults.
- Adjust settings — Change options like units, rates, or timeframes to match your specific scenario.
- Review results — The output shows a clear breakdown so you understand how the total was calculated.
How It Works
The US Navy method uses neck and waist circumference (plus hip for women). 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.
Real-World Example
Scenario: A 35-year-old man, 5'10" (178 cm)
- Neck circumference: 15.5 inches.
- Waist circumference: 34 inches.
- Height: 70 inches.
Who Is This For?
This body fat calculator is designed for Health-conscious individuals tracking fitness goals, understanding body composition, and making informed wellness decisions.. It's intentionally simple — no complex signup forms, no data tracking, no distractions. Just enter your numbers and get the answer.
Pro Tip
Track your measurements over time rather than obsessing over single readings — trends are more meaningful than individual data points.
Things to Know
The body fat calculator provides instant, accurate results based on standard formulas and the values you enter. Whether you are planning a financial decision, tracking a health metric, or solving a practical problem, this tool gives you the numbers you need without requiring signup or account creation.
How to get the best results: Use accurate, up-to-date inputs for the most reliable calculations. When planning ahead, run multiple scenarios with different assumptions to understand the range of possible outcomes.
Note: This tool is designed for educational and planning purposes. For critical financial, medical, or legal decisions, always verify the results with a qualified professional who can evaluate your specific circumstances.
Explore More Health & Wellness
These related tools work well alongside the body fat calculator:
Frequently Asked Questions
How accurate is the US Navy method?
The US Navy method has an accuracy of approximately ±3% compared to DEXA scans (the gold standard) when measurements are taken correctly. It is significantly more accurate than BMI and comparable to consumer-grade bioimpedance scales for tracking changes over time.
Should I use this instead of seeing a doctor?
No. This tool provides educational estimates only. Always consult a healthcare professional for medical advice, diagnosis, or treatment.
How often should I use this tool?
Use it as often as you like. Tracking your results weekly or monthly can help you spot trends and monitor progress over time.
How accurate are the results?
Results are based on standard formulas and the values you enter. They are accurate for educational and planning purposes.
Is this tool really free?
Yes, completely free. No signup, no hidden charges, no usage limits. Use it as often as you need.
How to Use
Select your gender, then enter your measurements. Measure your neck just below the larynx, your waist at navel level, and your hips at the widest point (women only). Use a flexible tape measure and keep it snug but not tight.
This calculator uses the U.S. Navy circumference method, with accuracy of about 3-4% compared to hydrostatic weighing.
Body Fat Categories
| Category | Men (% body fat) | Women (% body fat) |
|---|---|---|
| Essential Fat | 2-5% | 10-13% |
| Athletes | 6-13% | 14-20% |
| Fitness | 14-17% | 21-24% |
| Average | 18-24% | 25-31% |
| Obese | 25% + | 32% + |