Body Fat Calculator
Estimate body fat percentage using the US Navy circumference method
Enter your measurements above to estimate your body fat percentage.
What is a Body Fat Calculator?
A body fat calculator estimates the percentage of your body weight that is fat tissue. This calculator uses the US Navy circumference method, which requires measurements of height, waist, neck, and (for women) hips. While not as precise as DEXA scans or hydrostatic weighing, it provides a reasonable estimate without any special equipment.
How to Use the Body Fat Calculator
- Select your sex and preferred unit system (metric or imperial)
- Enter your height, waist circumference, and neck circumference
- Women: also enter your hip circumference at the widest point
- Your estimated body fat percentage and category appear instantly
Features
- Uses the US Navy circumference method
- Supports metric (cm) and imperial (inches) measurements
- Separate formulas for male and female body composition
- Color-coded category: Essential Fat, Athletes, Fitness, Average, Obese
- 100% client-side — no data sent to any server
Frequently Asked Questions
Where should I measure my waist?
For men, measure at the navel. For women, measure at the narrowest point of the torso (natural waist). Take the measurement after exhaling normally — don't suck in or push out.
What is a healthy body fat percentage?
For men, 6–17% is considered athletic to fitness range, and 18–24% is average. For women, 14–24% is athletic to fitness, and 25–31% is average. These ranges vary by age — body fat naturally increases with age.
How accurate is the US Navy method?
The US Navy method has an error margin of approximately ±3–4% compared to DEXA scans. It's a practical field method used by the US military for fitness assessments. For clinical accuracy, consult a healthcare professional.