Body Fat Calculator
Estimate your body fat percentage using the official US Navy Circumference Method. Take circumference measurements of your neck, waist, and hips to check your body composition.
Body Fat Percentage
17%
Acceptable / AverageStandard Reference Table (ACE Guidelines):
How to Use the Body Fat Calculator
- Select your gender: **Male** or **Female** (the formula differs for each).
- Choose your unit type: **Metric (cm)** or **Imperial (inches)**.
- Measure and enter your height.
- Wrap a flexible measuring tape around your **neck** (just below the Adam apple) and enter the size.
- Wrap the tape around your **waist** (at the narrowest point for women or at the navel for men) and enter.
- For **women only**, measure your **hip** size at the widest horizontal point and input the value.
- Review your body fat percentage and see where you sit on the green, orange, and red classification scale.
US Navy Body Fat Calculation Formula
The US Navy Method estimates body fat by calculating the logs of waist, neck, hip, and height values (measured in inches):
BF% = 86.010 x log10(waist - neck) - 70.041 x log10(height) + 36.76
For Women:
BF% = 163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387
Why Measure Body Fat Percentage Over BMI?
While Body Mass Index (BMI) is a popular and fast metric, it only uses your weight and height. It does not account for muscle mass or body composition. For instance, a bodybuilder with high muscle density and low body fat might be classified as "overweight" or "obese" according to standard BMI scales. A body fat calculator solves this by directly estimating the percentage of your total weight that consists of adipose tissue (fat).
Tracking body fat is crucial for fitness planning. Losing body fat while preserving lean muscle mass is the primary goal of healthy weight loss. The US Navy Circumference Method is a highly accessible way to track this progress from home, requiring only a simple tape measure rather than expensive equipment.
Frequently Asked Questions
What is the US Navy Circumference Method for body fat?
Developed by the US Navy, this method estimates body fat percentage using body circumference measurements. For men, it uses height, neck, and waist size. For women, it includes hip size as well, providing a highly cost-effective and surprisingly accurate estimate.
How accurate is the US Navy body fat calculator?
When measurements are taken carefully, the Navy method is accurate to within 3% to 4% of dual-energy X-ray absorptiometry (DEXA) scans, which are the clinical gold standard. It is generally more accurate than home bioelectrical impedance (BIA) scales.
How do I measure my waist, neck, and hips properly?
Use a flexible measuring tape: measure your neck just below the larynx, waist at the narrowest point (usually just above the navel) for women or at the navel for men, and hips at the widest point for women. Keep the tape flat against the skin without compressing it.
What is a healthy body fat percentage range?
Healthy body fat percentages differ by gender. For men, a healthy range is typically 8% to 20% (with obese being 25% or more). For women, a healthy range is 15% to 30% (with obese being 32% or more).