Body Fat Calculator
Estimate your body-fat percentage with the U.S. Navy tape-measure method. Free body fat calculator with category ranges, fat and lean mass. Private.
This body fat calculator estimates your body-fat percentage using the U.S. Navy circumference method — the same tape-measure formula the Navy uses for fitness assessments. All you need is a soft tape measure and a few minutes. It's far more informative than weight or BMI alone because it estimates how much of you is fat versus lean mass (muscle, bone, organs and water).
Body-fat percentage is what actually changes when you train well: you can lose fat and gain muscle while the scale barely moves. Tracking this number over weeks tells you whether your programme is working.
Estimate your body fat %
Body-fat ranges by category
| Category | Men | Women |
|---|---|---|
| Essential fat | 2–5% | 10–13% |
| Athletes | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| Above average | 25%+ | 32%+ |
Ranges adapted from the American Council on Exercise (ACE). Women carry more essential fat than men for hormonal and reproductive reasons — the same percentage means different things by sex.
How to measure accurately
- Use a flexible tape and keep it snug but not compressing the skin.
- Measure on bare skin, standing relaxed, breathing normally — don't suck in.
- Neck: just below the Adam's apple, tape sloping slightly down at the front.
- Waist (men): horizontally at navel level. Waist (women): at the narrowest point.
- Hip (women): around the widest part of the buttocks.
- Take each measurement twice and average them for consistency.
The Navy method is typically within ~3–4% of a DEXA scan for most people — excellent for a free tape-measure method. Its real strength is tracking change: measure the same way every two weeks and watch the trend, which matters far more than any single reading.
Lowering body fat the right way
To drop body fat, run a modest calorie deficit (find yours with the TDEE calculator), keep protein high (protein calculator), and lift weights so the loss comes from fat, not muscle. The full playbook is in how to lose fat.
Sources & further reading
- Hodgdon JA, Beckett MB. "Prediction of percent body fat for U.S. Navy men and women from body circumferences and height." Naval Health Research Center, 1984.
- American Council on Exercise (ACE) — Percent body fat norms.
- Centers for Disease Control and Prevention — Assessing your weight.
External links are provided for reference and do not imply endorsement. arsenal.fit is an independent publisher and is not affiliated with any cited organisation.