Free tool
Body Fat Calculator — US Navy Tape Method
A tape-and-formula estimate of body fat percentage from your neck, waist and (for women) hip circumference — no calipers or scan needed, just a soft measuring tape.
What this number can’t tell you
One number, one day. The paid report turns it into a plan — the sections it feeds:
- 12-week program16 min
- 7-day meals6 min
- Decision trees6 min
How we compute this
This is the US Navy circumference method (Hodgdon & Beckett, US Navy Health Research Center, 1984) — a widely used, public-domain formula that estimates body fat from neck, waist and, for women, hip circumference, scaled by height. It's the same method used in Navy fitness assessments and most free online body-fat calculators.
Treat the number as an estimate, generally within about ±3-4% of a DEXA scan (the gold standard for body composition). It's precise enough to track whether you're trending up or down over weeks, but not precise enough to anchor a single decision on. We also show your waist against the Indian abdominal-obesity cut-off, since waist size on its own is a strong, simple risk marker.
Questions people ask
It's an estimate, typically within about ±3-4% of a DEXA scan for most people. That's good enough to see whether your body fat is trending down (or up) over a few weeks or months of consistent measuring, but it's not precise enough to treat any single reading as an exact number.