Body Fat Calculator
Estimate your body fat percentage with the U.S. Navy circumference method — just a tape measure needed. Enter your measurements to see your estimated percentage and fitness category.
Body Fat Calculator
Estimate your body fat percentage with the U.S. Navy circumference method — just a tape measure needed. Enter your measurements to see your estimated percentage and fitness category.
Used because the formula differs for men and women.
Measure just below the larynx.
Measure at the narrowest point, after breathing out.
- Essential fat
- Athletic
- Fitness
- Average
- Above average
This is an estimate from the U.S. Navy circumference method. Lab methods such as DEXA are more accurate.
This is an educational estimate, not medical advice. Consult a qualified professional.
Save & share your result
How the U.S. Navy method works
The U.S. Navy formula estimates body fat from body circumferences rather than skinfold callipers or lab equipment. It uses your height and neck and waist measurements (plus hip measurement for women), all in centimetres, inside a logarithmic equation:
For men: %fat = 495 ÷ (1.0324 − 0.19077 × log₁₀(waist − neck) + 0.15456 × log₁₀(height)) − 450. For women: %fat = 495 ÷ (1.29579 − 0.35004 × log₁₀(waist + hip − neck) + 0.22100 × log₁₀(height)) − 450. For accuracy, measure relaxed and breathe out before reading the tape; take each measurement twice and average it.
Body fat categories
Healthy body-fat ranges differ between men and women because women carry more essential fat. The gauge above uses widely used fitness categories:
- Essential fat: about 2–5% (men) or 10–13% (women) — the minimum needed for health.
- Athletes: roughly 6–13% (men) or 14–20% (women).
- Fitness: around 14–17% (men) or 21–24% (women).
- Average: about 18–24% (men) or 25–31% (women); higher values indicate excess fat.
How accurate is it?
The Navy method is convenient and reasonably consistent, but it is an estimate. It works from average body shapes, so unusual proportions can skew the result, and a small tape-measure error can change the number by a percentage point or two. Laboratory techniques such as DEXA scanning, hydrostatic weighing or air-displacement (Bod Pod) are considerably more precise.
For tracking progress, the most valuable use is trend over time: measure under the same conditions every few weeks and watch the direction of change rather than fixating on a single reading.
Measure more accurately
As an affiliate we may earn from qualifying purchases — at no extra cost to you.
Frequently asked questions
How accurate is the U.S. Navy body fat method?
It is a useful estimate, typically within a few percentage points of lab methods for average body types, but it is not a precise measurement. DEXA and hydrostatic weighing are more accurate.
Where exactly do I measure my waist and neck?
Measure your neck just below the larynx, and your waist at the narrowest point (around the navel) after breathing out. Women also measure the hips at their widest point. Keep the tape level and snug.
What is a healthy body fat percentage?
A common healthy "fitness" range is about 14–17% for men and 21–24% for women. Women naturally carry more essential fat, so their healthy ranges are higher than men’s.
Sources & references
- Hodgdon JA, Beckett MB. "Prediction of percent body fat for U.S. Navy men and women from body circumference measurements." Naval Health Research Center, Reports 84-11 & 84-29, 1984.
- World Health Organization. "Obesity and overweight" fact sheet (BMI classification and health risks).
Not medical advice. This result is an educational estimate from HealthyLifeStyles (Trusted Wellness), based on population formulas — not a diagnosis or treatment. Always consult a qualified healthcare professional about your health.
https://www.healthylifestyles.com/tools/body-fat-calculator