Body Fat Calculator
Estimate body fat with U.S. Navy circumference and BMI methods. Educational only.
Body fat calculator
Estimates body fat with the U.S. Navy circumference method and a BMI-based method. Measure to the nearest 0.5 cm (¼ in). Educational only — not a clinical measurement.
Result
The American Council on Exercise Body Fat Categorization
| Description | Women | Men |
|---|---|---|
| Essential fat | 10–13% | 2–5% |
| Athletes | 14–20% | 6–13% |
| Fitness | 21–24% | 14–17% |
| Average | 25–31% | 18–24% |
| Obese | 32%+ | 25%+ |
Jackson & Pollock Ideal Body Fat Percentages
| Age | Women | Men |
|---|---|---|
| 20 | 17.7% | 8.5% |
| 25 | 18.4% | 10.5% |
| 30 | 19.3% | 12.7% |
| 35 | 21.5% | 13.7% |
| 40 | 22.2% | 15.3% |
| 45 | 22.9% | 16.4% |
| 50 | 25.2% | 18.9% |
| 55 | 26.3% | 20.9% |
Measuring body fat percentage
The U.S. Navy method uses equations developed at the Naval Health Research Center (Hodgdon & Beckett, 1984). Measure waist at the navel for men and at the narrowest width for women; neck below the larynx; and for women, hips at the largest horizontal circumference.
Men (metric):
BFP = 495 ÷ (1.0324 − 0.19077×log₁₀(waist−neck) + 0.15456×log₁₀(height)) − 450
Women (metric):
BFP = 495 ÷ (1.29579 − 0.35004×log₁₀(waist+hip−neck) + 0.22100×log₁₀(height)) − 450
Fat mass = body-fat fraction × weight. Lean mass = weight − fat mass. The BMI method uses age and BMI (adults: men 1.20×BMI + 0.23×Age − 16.2; women 1.20×BMI + 0.23×Age − 5.4). Results are estimates only.
Health disclaimer
This calculator is educational. Circumference and BMI-based body-fat estimates are not medical advice, a diagnosis, or a substitute for clinical body-composition testing. Speak with a qualified clinician before making health decisions.
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