Health & Fitness
Body Fat Estimate (Navy Method) Calculator
Estimate body fat percentage from tape measurements using the US Navy circumference method.
The result is an estimate of body fat percentage from tape measurements, so 16.9% means roughly that share of total body weight is estimated as fat, with tape placement able to shift the figure by a few percentage points.
Formula
For men the Navy formula uses waist, neck and height; for women it adds hip measurement, all combined with base-10 logarithms.
How it works
Tape measurements are fed into the Navy equation, which estimates body density and converts it to a fat percentage. Measure waist at the navel, neck below the Adam's apple, and hip at the widest point, keeping the tape snug but not tight.
Worked example
For example, for a man with a waist of 85 cm, a neck of 38 cm and a height of 175 cm, the Navy equation gives a body density of 1.0601, and 495 divided by 1.0601 minus 450 equals 16.9%.
FAQs
How accurate is it?
Within a few percentage points for many adults, but tape placement alone can shift it.
Why does it ask for neck size?
Neck size helps adjust for frame size in the Navy equation.
Can it replace a scan?
No. Scans and calipers measure differently; this is a free rough estimate.
General information only, not medical advice.
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