Body Fat Calculator

Free body fat calculator. Estimate your body fat percentage using the US Navy method with circumference measurements.

How the Body Fat Calculator works

The US Navy method estimates body fat from circumference measurements using logarithmic regression equations. It subtracts neck from waist (and hip for women), takes the log, and combines it with height to derive a density value that converts to a body fat percentage.

Formula

BF% (men) = 495 / (1.0324 − 0.19077×log₁₀(waist−neck) + 0.15456×log₁₀(height)) − 450

How to use the Body Fat Calculator

  1. 1The body fat calculator is designed to be simple and fast.
  2. 2Select your gender.
  3. 3Enter your height, neck, and waist measurements.
  4. 4For women, also enter hip measurement.
  5. 5Your result is shown immediately.

Examples

  • Male, 175cm, 38cm neck, 85cm waist = ~15% body fat
  • Female, 165cm, 33cm neck, 75cm waist, 95cm hip = ~22% body fat

Benefits

  • Completely free with no signup required.
  • Runs entirely in your browser for instant results and privacy.
  • Works on mobile, tablet and desktop.
  • Results can be copied with one click.

Frequently Asked Questions

Is the body fat calculator free to use?

Yes. The body fat calculator is 100% free, with no signup, no watermark and no hidden limits.

Does the body fat calculator store my data?

No. All calculations and processing happen locally in your browser. Nothing is uploaded to a server.

Does the body fat calculator work on mobile?

Yes. The body fat calculator is fully responsive and works on phones, tablets and desktop computers.

What is the US Navy body fat method?

It uses circumference measurements (neck, waist, and hip for women) along with height to estimate body fat percentage.

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