Body Fat Percentage Calculator (US Navy)
Body Fat % Calculator (US Navy Method)
Tape-measure body fat % using the US Navy circumference formula — no calipers needed.
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Frequently Asked Questions
Q1How does the US Navy body fat formula work?
The US Navy method estimates body fat percentage using circumference measurements (neck, waist, and hips for women) alongside height. It applies a logarithmic formula validated against hydrostatic weighing data, making it more accurate than BMI for muscular individuals while requiring only a flexible measuring tape.
Q2How accurate is the US Navy body fat calculator?
The Navy formula has a margin of error of approximately ±3–4% body fat compared to gold-standard DEXA scanning. Accuracy improves with careful, consistent measurements. It is more reliable than BMI but less precise than DEXA, BodPod, or hydrostatic weighing for individuals with atypical body composition.
Q3Where exactly should I measure my waist and neck for accurate results?
Neck: measure at the narrowest point, just below the larynx (Adam's apple), with the tape perpendicular to the long axis of the neck. Waist: measure at the navel for men; at the narrowest point of the abdomen for women. Take measurements after a normal exhale and ensure the tape is level and snug but not compressing skin.
Q4What are healthy body fat percentage ranges for men and women?
Men — Essential fat: 2–5% | Athletes: 6–13% | Fitness: 14–17% | Acceptable: 18–24% | Obese: 25%+. Women — Essential fat: 10–13% | Athletes: 14–20% | Fitness: 21–24% | Acceptable: 25–31% | Obese: 32%+. These ranges are general guidelines; optimal levels vary by age and individual health status.