📊 Body Fat % Estimator
Estimate your body fat percentage with the U.S. Navy tape-measure method.
Measure just below the larynx (Adam's apple).
Men: at the navel. Women: at the narrowest point.
Your Body Fat %
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The U.S. Navy method, explained
The Navy circumference method estimates body fat from a few tape-measure readings rather than skinfold calipers or a lab scan. It works because fat tends to distribute in predictable places, so the relationship between your waist, neck, height (and hip, for women) correlates with overall body-fat percentage. For men it uses neck and waist; for women it adds the hip measurement, which is why this calculator shows a hip field only when you select female.
Measuring accurately
Use a flexible tape, keep it level, and don't pull it tight enough to compress the skin. Measure relaxed — don't suck in your stomach. Because small differences in technique shift the result, the method is most useful for tracking change over weeks and months: measure the same way each time. It pairs naturally with the BMI calculator (which can't see composition) and the TDEE calculator for setting calories to shift your body fat in either direction.
Worked example
For a man who is 70 inches tall with a 16-inch neck and a 36-inch waist, the U.S. Navy formula returns about 19% body fat — toward the lower end of the "average" range for men. A woman adds her hip measurement, and the female version of the formula uses waist + hip − neck.
Accuracy and limitations
- The Navy method typically lands within a few percentage points of lab methods like DEXA, but it's still an estimate, not a scan.
- Measurement technique drives most of the error — keep the tape level, snug but not compressing, and measure relaxed.
- It's most useful for tracking change over time: measure the same way each time and watch the trend rather than fixating on a single number.
Sources & references
This tool uses the U.S. Navy circumference method, developed by Hodgdon, J.A. & Beckett, M.B. (1984) at the Naval Health Research Center for estimating body fat from neck, waist, height, and (for women) hip measurements. For how body composition relates to overall health, the CDC's overview of body weight and health is a useful companion reference.