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Body Fat Calculator

Estimate your body fat percentage using the US Navy method. Just enter a few simple measurements.

Body Fat Calculator

Understanding Body Fat Percentage

Body fat percentage is the proportion of your total body weight that is made up of fat tissue. Unlike BMI, which only considers height and weight, body fat percentage gives a more accurate picture of your body composition by distinguishing between fat mass and lean mass (muscle, bone, water, and organs).

CategoryMenWomen
Essential Fat2–5%10–13%
Athletes6–13%14–20%
Fitness14–17%21–24%
Average18–24%25–31%
Obese25%+32%+

How the Navy Method Works

The US Navy method uses circumference measurements to estimate body fat. For men, the formula uses height, waist circumference, and neck circumference. For women, it also includes hip circumference. These measurements are plugged into a logarithmic equation developed by Hodgdon and Beckett (1984) that has been shown to correlate closely with hydrostatic weighing results.

Limitations

The Navy method may be less accurate for individuals with unusual body proportions, very high or very low body fat levels, or significant muscle mass. It relies on tape measurements, which introduce operator error. For the most accurate results, measure in the morning before eating, keep the tape snug but not compressing the skin, and take each measurement twice. For clinical-grade accuracy, consider a DEXA scan.

Disclaimer: This calculator is for informational purposes only and is not a substitute for professional medical advice. Always consult a healthcare provider for personalized health assessments.

Frequently Asked Questions

How does the US Navy body fat method work?
The US Navy method estimates body fat percentage using circumference measurements. For men, it uses neck and waist measurements along with height. For women, it adds a hip measurement. These values are plugged into a logarithmic formula that has been validated against hydrostatic weighing and correlates well with more expensive body composition tests.
How accurate is the Navy method compared to other methods?
The Navy method is generally accurate within 3-4% of results from hydrostatic weighing or DEXA scans for most people. It can be less accurate for very lean or very obese individuals. For a free, at-home test it provides a solid estimate, but for clinical precision consider a DEXA scan or Bod Pod assessment.
What is a healthy body fat percentage?
Healthy body fat ranges vary by gender. For men, 14-17% is considered the fitness range, while 18-24% is average. For women, 21-24% is fitness and 25-31% is average. Essential fat levels (below which health risks increase) are 2-5% for men and 10-13% for women. Athletes often fall in the 6-13% (men) or 14-20% (women) range.
How often should I measure my body fat?
For most people tracking body composition changes, measuring once every 2-4 weeks is sufficient. Body fat doesn't change rapidly, so daily measurements will mostly reflect measurement error. Always measure at the same time of day, under the same conditions, for consistent comparisons.

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