Body Fat Calculator

Calculate body fat percentage using the US Navy circumference method and BMI-based estimate. Get lean body mass, fat mass, category, and age-group ideal ranges.

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Body Fat Calculator

Calculate body fat percentage using the US Navy method and BMI-based estimate. Get lean body mass, fat mass, category (Essential/Athletes/Fitness/Average/Obese), and ideal ranges for your age group. Metric/imperial toggle, copy, and CSV export.

Your Measurements

Measure neck just below the larynx, waist at the navel (men) or narrowest point (women), and hip at the widest point. Keep the tape snug but not tight.

Body Fat Percentage

US Navy Method (Primary)
16.5%
Based on circumference measurements
BMI Method (Secondary)
21.0%
Deurenberg formula (BMI 25.2)
Fitness
Fit and lean
Ideal Range for Age Group
For men age 30: 13% – 19%
Within ideal range

Frequently Asked Questions

How accurate is the US Navy method?

Typically within 3-4% of hydrostatic weighing when tape measurements (neck, waist, hip) are taken consistently. Less accurate for very lean athletes or unusual body proportions.

What is a healthy body fat %?

Men: 14-24% healthy, 6-13% athlete. Women: 21-31% healthy, 14-20% athlete. Essential fat is ~2-5% (men) and ~10-13% (women).

Navy method vs BMI method — which is better?

Navy uses actual circumferences so it reflects fat distribution and is generally more accurate for individuals. BMI method cannot distinguish muscle from fat and overestimates for muscular people.

Is the Body Fat Calculator free to use?

Yes, the Body Fat Calculator is 100% free with no registration, no hidden fees, and no usage limits. All processing happens locally in your browser, ensuring complete privacy.

Is my data safe with this tool?

Absolutely. The Body Fat Calculator processes everything client-side in your browser. No data is uploaded to or stored on any server. Your content remains private on your device at all times.

Does the Body Fat Calculator work on mobile devices?

Yes, the Body Fat Calculator is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.

Do I need to create an account to use this tool?

No account or registration is needed. Simply open the Body Fat Calculator in your browser and start using it immediately. There are no sign-up walls or usage restrictions.

How do I use the Body Fat Calculator?

Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.

Which browsers are supported?

The Body Fat Calculator works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.

About Body Fat Calculator

Body Fat Calculator is a free, browser-based tool in our Calculator Tools collection. Everything runs locally on your device — no uploads, no sign-up, and your data stays private.

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