Body Fat Calculator
Estimate your body fat percentage with the US Navy tape method and see it against plain reference ranges.
Measure with a soft tape, snug but not tight. Take the waist at the navel, the neck just below the larynx, and the hip at its widest.
Enter your measurements to estimate your body fat.
How to use the body fat calculator
The US Navy method needs a few tape measurements and your height. Men enter neck and waist; women add a hip measurement, since the formula differs by sex.
- Choose centimeters or inches and select your sex.
- Enter your height, neck, and waist measurements.
- If you selected female, add your hip measurement.
- Read your estimated body fat percentage and the plain reference range it falls into.
How the US Navy method works
This method estimates body fat from body circumferences rather than weight. The idea is that fat distributes in predictable ways, so the gap between waist and neck, set against height, tracks with overall body fat. Women add the hip, which improves the estimate for the way fat tends to sit.
It is quick and needs only a tape measure, which is why the military adopted it for routine screening. It is an estimate, though, not a lab measurement, and accuracy depends on measuring carefully and at the right spots.
What body fat percentage means
Body fat percentage is the share of your weight that is fat tissue. The rest is lean mass: muscle, bone, organs, and water. It adds detail that weight alone misses, since two people at the same weight can carry very different amounts of fat and muscle.
Some body fat is essential. It cushions organs, stores energy, and supports hormones, which is why an essential range exists at the low end for each sex. There is no single right number. A healthy amount spans a broad band and shifts with age, sex, and individual makeup.
Reading the reference ranges
The categories shown come from the American Council on Exercise and describe common ranges, not grades. They differ by sex because women naturally carry more essential fat.
- Men: essential 2 to 5%, athletic 6 to 13%, fitness 14 to 17%, average 18 to 24%.
- Women: essential 10 to 13%, athletic 14 to 20%, fitness 21 to 24%, average 25 to 31%.
Lower is not automatically better. Dropping into or below the essential range can harm health. Read your result as one data point among many, and bring questions about it to a health professional.
Frequently asked questions
- How accurate is the US Navy body fat method?
- It is a reasonable estimate for most people, usually within a few percentage points of more advanced methods. Accuracy depends on careful measuring. Methods like DEXA scans are more precise but need special equipment.
- What is a healthy body fat percentage?
- There is no single healthy number. Ranges vary by age and sex, and a broad band is considered healthy for each. Some fat is essential for the body to function, so both very high and very low figures carry their own risks.
- Why do men and women have different ranges?
- Women naturally carry more essential fat, partly to support reproductive health, so healthy ranges sit higher for women than for men. The calculator uses a separate formula and separate reference ranges for each.
- How should I measure for the best result?
- Use a flexible tape held snug but not tight. Measure the neck just below the larynx, the waist at the navel, and, for women, the hip at its widest point. Taking each measurement twice and averaging helps.
- Is a lower body fat percentage always better?
- No. Body fat plays essential roles, from protecting organs to supporting hormones, and dropping too low can affect energy, mood, and health. A healthy range matters more than the lowest possible number. A professional can advise on what fits you.