NAVY METHOD
BODY FAT
Estimate your body fat percentage using the US Navy circumference formula — just enter a few tape-measure readings for an instant result.
The US Navy Body Fat Formula
The US Navy circumference method was developed for use across military populations and remains one of the most widely used field-based body fat estimation techniques. For men, it uses neck and waist measurements; for women, neck, waist, and hip measurements. In published comparisons against DEXA scans, it tends to land within about 3–4 percentage points for people with an average build.
How to Measure Correctly
Neck: measure at the narrowest point, below the larynx. Waist: measure at the narrowest point (men) or at the navel (women). Hips (women only): measure at the widest point. Use a flexible, non-stretch tape measure, keep it snug but not compressing the skin, and take each measurement first thing in the morning before eating or drinking for the most consistent results.
What This Estimate Can (and Can't) Tell You
The Navy method estimates body fat percentage from body circumferences rather than measuring fat tissue directly, so treat the result as a useful approximation, not a diagnostic-grade reading. It can be less accurate for people who are very muscular, very lean, or who carry weight in a way that doesn't match the general population the formula was built on. For a more precise reading, methods such as DEXA, hydrostatic weighing, or air displacement plethysmography (Bod Pod) are considered more reliable, though far less convenient for everyday tracking. This calculator is intended to help you monitor trends over time, not to diagnose a medical condition.