Body Fat Percentage Calculator
US Navy tape method with fat mass and lean mass. Free, private and instant.
How to use the Body Fat Percentage
- Pick metric (cm, kg) or imperial (ft, in, lb) units.
- Choose sex: Male or Female.
- Enter age.
- Enter height.
- Enter weight.
- Enter neck circumference.
- Enter waist circumference.
- Answer any extra questions that appear for your choices.
- Press Calculate to get an instant result with a colour scale, chart and plain-English explanation.
About the Body Fat Percentage
Body fat percentage is the share of your weight that is fat. This calculator uses the US Navy circumference method with your height, waist, neck and (for women) hip measurements, and compares it with a BMI-based estimate.
Also known as: body fat percentage calculator, US Navy body fat calculator, body fat estimator, tape measure body fat calculator.
Worked example
- Sex: Male
- Age: 30 years
- Height: 170 cm
- Weight: 70 kg
- Neck circumference: 38 cm
- Waist circumference: 84 cm
Body fat (US Navy): 17.0 % (Fitness). Your estimated body fat is 17.0%, in the "Fitness" range for men.
- Body fat: 17.0%
- Category: Fitness
- Fat mass: 11.9 kg
- Lean mass: 58.1 kg
Formula and cut-offs
Men: 495 / (1.0324 - 0.19077 x log10(waist - neck) + 0.15456 x log10(height)) - 450. Women: 495 / (1.29579 - 0.35004 x log10(waist + hip - neck) + 0.22100 x log10(height)) - 450. Measurements in cm.
Frequently asked questions
How accurate is the Navy body fat method?
It is typically within about 3 to 4 percentage points of DEXA scans for most people. Measure at the same spots each time for consistent tracking.
What is a healthy body fat percentage?
Roughly 14-24% for men and 21-31% for women covers fitness to average ranges. Essential fat is about 2-5% for men and 10-13% for women.
How do I measure neck, waist and hips?
Measure the neck just below the larynx, the waist at the navel for men or at the narrowest point for women, and the hips at the widest point. Keep the tape level and snug but not compressing the skin.
Can I calculate body fat from BMI?
Only roughly. BMI-based estimates ignore where you carry fat and cannot separate muscle from fat. A tape method such as the US Navy formula usually gives a closer estimate for most adults.
Sources and references
- World Health Organization - Obesity and overweight fact sheet
- WHO - Waist circumference and waist-hip ratio: report of a WHO expert consultation
Written and checked by the MediHub editorial team against the sources above. Read how we build and review our calculators.
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Last updated . This calculator is for education only and is not medical advice. See the medical disclaimer.