Body Fat Calculator

Estimate your body fat percentage with the US Navy tape method, using a few simple measurements, and see your fat and lean mass.

Read the guide: How to Estimate Body Fat at Home

Your measurements

Units
Sex

Estimated body fat

18.8%

Average

Fat mass
15 kg
Lean mass
65 kg

Body fat

18.8%

  • Lean mass81%
  • Fat mass19%

The US Navy tape method is an estimate and can differ from a scan. Informational only, not medical advice.

How it works

  1. 1

    Measure up

    Take your neck and waist (and hip for women) with a tape measure.

  2. 2

    Enter the numbers

    Add your sex, height, weight and the measurements.

  3. 3

    See your estimate

    View your body fat percentage, category, and fat and lean mass.

Instant & 100% private — nothing is uploaded

Every calculation runs locally in your browser. The measurements, dates and details you enter stay on your own device and are never sent to a server — nothing is stored, logged or shared.

Frequently asked questions

How accurate is the tape method?
The US Navy method is reasonably good for tracking change over time, but it is an estimate. A DEXA scan or calipers in trained hands are more precise.
How should I take the measurements?
Measure relaxed, without pulling the tape tight. Waist at the navel, neck below the larynx, hips at the widest point. Consistency matters most for tracking.
Is this medical advice?
No. These calculators are for general information and education only. They are not a diagnosis or a substitute for professional care — talk to a doctor or qualified clinician about your health.