Body Fat Calculator
Estimate your body fat percentage using the U.S. Navy tape method. Enter your measurements in inches. This is a general estimate, not a medical or clinical body-composition test.
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Check it outAbout the Navy method
The U.S. Navy formula estimates body fat from a few tape measurements: neck and waist for everyone, plus hips for women, all relative to height. It's free and surprisingly consistent, but it's an estimate — not as precise as a DEXA scan or calipers in trained hands. Measure snugly and consistently, and treat results as a trend rather than an exact figure. This isn't medical advice.
How it’s calculated
U.S. Navy method: body fat % from a logarithmic formula using neck, waist (and hips for women) relative to height.
Results update as you type and are estimates, not professional advice — verify important decisions with a qualified professional.
Sources: U.S. Navy body fat method.
Worked example
A man 70 inches tall with a 34-inch waist and 15-inch neck estimates about 17.5% body fat (fitness range).
Common mistakes
- Measuring the waist or neck in the wrong place.
- Treating an estimate like a clinical body-composition test.
Where it is used
- Tracking body-fat trends over time.
- Setting a fitness target alongside weight.
Frequently asked questions
How accurate is it?
Reasonably good for tracking trends, typically within a few percent. Clinical methods like DEXA are more precise.
Where do I measure?
Waist at the navel, neck just below the larynx, hips at the widest point. Keep the tape level and snug, not tight.
Do women need the hip measurement?
Yes — the female formula requires neck, waist, and hip. Men use neck and waist only.
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