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ToolWrenEstimate your body fat percentage using the U.S. Navy tape-measure method, based on a few body measurements.
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Body Fat is a free, private online tool that lets you estimate body fat percentage using the U.S. It runs entirely in your browser, so nothing you enter is uploaded to a server.
Privacy: this tool runs entirely in your browser. Your input is never sent to, received by, or stored on any server — there are no uploads and no tracking of what you enter.
This widely used method estimates body fat from neck, waist (and hip for women) and height measurements — no special equipment beyond a tape measure.
Body fat percentage describes composition better than weight or BMI alone, distinguishing muscle from fat.
Results map to ranges such as essential, athlete, fitness, average and above average. Treat them as estimates.
Body fat percentage is the proportion of your total weight that is fat, as opposed to muscle, bone, organs and water. It describes body composition rather than just weight, which makes it a more informative health and fitness measure than the scale alone - two people of identical weight can have very different body-fat levels.
This calculator uses the U.S. Navy circumference method, which estimates body fat from a few tape-measure measurements - neck, waist, and (for women) hips - together with height. It was developed so body composition could be assessed without special equipment, and it correlates reasonably well with more expensive methods for most people.
Unlike BMI, body fat percentage distinguishes fat from lean mass. A muscular person flagged as overweight by BMI may have an athletic body-fat percentage. Tracking body fat is therefore more useful for fitness goals, since it shows whether you are losing fat or muscle when your weight changes - which the scale alone cannot tell you.
Results map to broad ranges - essential, athlete, fitness, average and above-average - which differ for men and women because women naturally carry more essential fat. Treat the number as an estimate: tape-measure methods are less precise than DEXA scans or calipers, and measurement technique affects accuracy, so measure carefully and consistently.
Estimate body composition without a gym or clinic, track fat loss during training (alongside weight), and set realistic fitness targets. Measure in the same conditions each time for comparable results. Everything is calculated locally in your browser.