Body Fat Calculator
Estimate body fat percentage from neck, waist, and hip measurements.
Estimate body fat percentage using the U.S. Navy circumference method — no calipers or scan needed, just a tape measure around the neck, waist, and (for women) hips.
General body fat categories (adults)
| Category | Women | Men |
|---|---|---|
| Essential fat | 10–13% | 2–5% |
| Athletes | 14–20% | 6–13% |
| Fitness | 21–24% | 14–17% |
| Average | 25–31% | 18–24% |
| Obese | 32%+ | 25%+ |
Frequently asked questions
What formula does this use?
The U.S. Navy circumference method (Hodgdon & Beckett, 1984) — it estimates body fat percentage from neck, waist, and (for women) hip measurements instead of requiring calipers or a scan.
How do I measure my waist and neck correctly?
Measure your neck just below the larynx (Adam's apple), and your waist at the narrowest point (or at the navel if there's no clear narrowing) — keep the tape snug but not compressing the skin, and measure standing relaxed.
How accurate is this compared to a DEXA scan or calipers?
The Navy method is typically within about 3-4% of more precise methods like DEXA for most people, which makes it a solid free estimate — but it's not a clinical measurement.
Can I enter measurements in inches instead of centimeters?
Yes — use the Metric/Imperial toggle above the form. Switching units automatically converts any values you've already typed, so the numbers keep meaning the same physical measurement rather than being reinterpreted in the new unit.
This tool provides a general estimate and isn't a substitute for a clinical body composition test.