Body Fat Percentage Calculator
Calculate body fat percentage, lean body mass, and fat mass using the US Navy tape method.
- 100% free
- Private in browser
- No signup
- No watermarks
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About Body Fat Percentage Calculator
Estimate your body fat percentage accurately using the U.S. Navy body composition formula. Using simple tape measurements (neck, waist, and hip circumferences), find your fat percentage, lean body mass, and fitness category.
How to use Body Fat Percentage Calculator
- Select Gender: Male or Female.
- Enter Height, Weight, Neck circumference, and Waist circumference (plus Hip for females).
- View your calculated Body Fat %, Fat Mass, Lean Body Mass, and Fitness Category.
Key features
- Proven U.S. Navy Department of Defense formula
- Supports Men and Women with specific physiological equations
- Metric (cm, kg) and Imperial (inches, lbs) support
- Classifies body composition: Essential fat, Athletes, Fitness, Average, or Obese
- 100% private in-browser calculation
Frequently asked questions
- What is the U.S. Navy Body Fat method?
- The U.S. Navy method uses circumference measurements of the neck, waist (and hips for females) compared against height to calculate body density and fat percentage with high clinical accuracy.
- How should I measure my waist and neck?
- Measure neck circumference just below the larynx, and measure waist at the narrowest point or navel level while relaxed.
- What do I need to enter?
- Just Biological Sex, Height, Weight, Neck Circumference and Waist Circumference and a few optional settings. Every field has a sensible default you can start from.
- Is my data uploaded anywhere?
- No. The calculation runs in your browser with JavaScript — nothing you type is sent to a server or stored.
- Does it work on a phone?
- Yes. The layout adapts to small screens and needs no app or signup.
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