Estimate your body fat percentage with the US Navy tape-measure method.
18.37%
Category
Average
Fat mass
14.69
Lean mass
65.31
The US Navy body fat method is a quick, tape-measure-based field estimate of body composition. It uses just three measurements—neck, waist, and hip circumference (plus height)—and applies logarithmic regression to derive an estimate of body fat percentage. Unlike expensive imaging like DEXA, it requires no equipment beyond a cloth tape measure and takes less than a minute. The Navy originally developed it for personnel screening and fitness tracking; today it remains one of the most accessible body composition estimates available. That accessibility comes with a trade-off: the method has a typical error margin of ±3–5% compared to more precise laboratory methods. It tends to underestimate fat in very lean individuals and overestimate in the very obese. Still, it is far more informative than BMI alone, since it separates lean mass (muscle, bone, organs) from fat mass—the latter being what health risk correlates with.
A 180 cm tall male with a neck circumference of 40 cm and waist of 90 cm has an estimated body fat of approximately 18.4%. Weighing 80 kg, this works out to about 14.7 kg of fat mass and 65.3 kg of lean mass. This category falls into the "Average" range.
Women must also measure hip circumference, which is not required for the male formula. For example, a 165 cm tall woman with a neck of 34 cm, waist of 80 cm, and hip of 100 cm would have a different body fat estimate than the same waist measurement alone would suggest, because the hip adds context about body composition distribution.
How accurate is the Navy body fat method?
The US Navy method typically has an error range of ±3–5% compared to gold-standard measurements like DEXA. It is much more reliable than BMI for body composition, but less precise than laboratory methods. It works best on average, fit, and modestly overweight individuals; results are less reliable in very lean athletes and very obese individuals.
How do I measure my waist and neck?
For the waist: place the tape measure horizontally around your natural waist (at the narrowest point, typically at the navel level), with the tape snug but not compressing the skin. For the neck: wrap the tape around the base of your neck (just below your larynx), again snug but not tight. Women should also measure around the fullest part of the hip, keeping the tape level and parallel to the floor. Take measurements in the morning when swelling is minimal, and repeat each measurement twice to ensure consistency.
What is a healthy body fat percentage?
Body fat ranges vary by age and sex. For adult men, 10–20% is generally considered "fitness" to "average" range, with below 6% being essential fat and above 25% considered above average. For women, 18–28% is typically "fitness" to "average," with below 14% essential fat and above 32% above average. Athletes may be lower; sedentary individuals typically higher. Consult your healthcare provider about what is appropriate for your age, health history, and goals.