How This Calculator Works
Use this body fat tool for quick estimation, comparison, and planning intent while keeping formula assumptions visible.
Use the body fat percentage calculator to estimate body fat using height, neck, waist, sex, and hip measurement where applicable.
The US Navy method estimates body fat from circumference measurements. It is a screening estimate, not a lab measurement.
Formula
Male: 86.010 log10(waist - neck) - 70.041 log10(height) + 36.76. Female: 163.205 log10(waist + hip - neck) - 97.684 log10(height) - 78.387.
Example Calculation
A 70 inch tall male with 34 inch waist and 15 inch neck estimates about 20% body fat.
When to Use This Calculator
- Track body composition trends
- Compare circumference changes
- Estimate fitness progress
Practical Scenarios
- Use the Body Fat Percentage Calculator to track body composition trends while comparing at least one conservative and one higher-cost scenario.
- Use the Body Fat Percentage Calculator to compare circumference changes while comparing at least one conservative and one higher-cost scenario.
- Use the Body Fat Percentage Calculator to estimate fitness progress while comparing at least one conservative and one higher-cost scenario.
Tips
- Measure consistently
- Use trends more than one reading
- Professional methods may differ materially
Common Mistakes
- Measuring over clothing
- Using centimeters in inch fields
- Treating the estimate as diagnostic
- Using a best-case input when a realistic range would be safer.
- Forgetting fees, taxes, inflation, usage changes, or other hidden costs where they apply.
Assumptions and Limitations
The Body Fat Percentage Calculator is most accurate when the inputs match current real-world numbers and when you review the formula, assumptions, and related calculators before acting.
- Age, medical history, body composition, medication, training status, and personal context can change what the result means.
- The result is informational and is not medical advice, diagnosis, or treatment.
- Use health estimates as a starting point for discussion with a qualified professional when needed.