Body Fat Calculator
Estimate body fat percentage from body measurements using the U.S. Navy method, in imperial or metric units.
Frequently Asked Questions
How does the U.S. Navy method work?+
It estimates body fat from circumference measurements and height using a validated formula. For men it uses neck and waist; for women it adds hip. These measurements correlate with body fat, so the method gives a reasonable estimate without calipers or special equipment.
Where do I take the measurements?+
Measure your neck just below the larynx, your waist at the navel (men) or at the narrowest point (women), and — for women — your hips at the widest point. Keep the tape snug but not compressing the skin, and measure on bare skin for consistency.
How accurate is this estimate?+
The Navy method is typically within a few percentage points of more precise methods like DEXA for most people, but accuracy depends on measuring carefully and consistently. It is a useful way to track change over time rather than an exact clinical value.
Is my data private?+
Yes. All calculations run in your browser. Your measurements are never sent to a server or stored.
Related Calculators
How to use
- Pick Imperial (ft + in, in) or Metric (cm) units.
- Choose your sex and enter your measurements — in imperial, enter height as feet and inches.
- Men enter neck and waist; women also enter hip.
- Your estimated body fat percentage and category appear instantly.