Body Fat Calculator
Calculate your body fat percentage using the US Navy circumference method. Enter your measurements for instant results — see your category, lean mass, and fat mass.
Your body composition
Navy method estimates are within ±3-4% accuracy. For clinical precision, use a DEXA scan or hydrostatic weighing.
Understanding body fat percentage
Your body fat percentage is the proportion of your total weight that comes from fat, as opposed to muscle, bone, water, and organs. It's a more meaningful health metric than BMI, which doesn't distinguish between fat and muscle mass.
The US Navy body fat method
This calculator uses the US Navy circumference method, which estimates body fat from measurements of the neck, waist (and hip for women) combined with height. The formulas are: Men: 495 ÷ (1.0324 − 0.19077 × log₁₀(waist − neck) + 0.15456 × log₁₀(height)) − 450. Women: 495 ÷ (1.29579 − 0.35004 × log₁₀(waist + hip − neck) + 0.22100 × log₁₀(height)) − 450.
Healthy body fat ranges (ACE)
Men: Essential 2-5%, Athletes 6-13%, Fitness 14-17%, Average 18-24%, Obese 25%+. Women: Essential 10-13%, Athletes 14-20%, Fitness 21-24%, Average 25-31%, Obese 32%+.
Related: BMR Calculator · BMI Calculator · Macro Calculator
· Reviewed by the Vital Health Editorial Team
How This Calculator Works
This calculator estimates body fat percentage using the U.S. Navy Circumference Method, developed by the Naval Health Research Center. The formulas are:
Men: %BF = 495 / (1.0324 − 0.19077 × log₁₀(waist − neck) + 0.15456 × log₁₀(height)) − 450
Women: %BF = 495 / (1.29579 − 0.35004 × log₁₀(waist + hip − neck) + 0.22100 × log₁₀(height)) − 450
All measurements in centimeters. The Navy method is accurate within ±3–4% of DEXA scans. Essential body fat minimums are ~2–5% for men and ~10–13% for women. Healthy ranges: men 10–20%, women 18–28%.
For informational purposes only — not a substitute for professional body composition testing.
Frequently Asked Questions
How accurate is the Navy body fat method?
The Navy circumference method is accurate within ±3–4% of DEXA scan results for most people. It is more accurate than BMI for assessing body composition. However, it can be less accurate for very muscular or very lean individuals. For clinical accuracy, DEXA scans or hydrostatic weighing are the gold standards.
What is a healthy body fat percentage?
According to the American Council on Exercise: essential fat is 2–5% (men) and 10–13% (women). Athletes: 6–13% (men), 14–20% (women). Fitness: 14–17% (men), 21–24% (women). Average: 18–24% (men), 25–31% (women). Obese: 25%+ (men), 32%+ (women).
How do I measure my waist and neck correctly?
Measure waist at the navel (belly button) level, keeping the tape horizontal and relaxed (not sucked in). Measure neck at the narrowest point, below the larynx (Adam's apple). For women, also measure hips at the widest point. Measure in the morning before eating for consistency. Use a flexible, non-stretch measuring tape.
Sources & References
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