fitness performance tool

Body Fat Calculator

Estimate your body fat percentage using the US Navy Method based on simple body tape measurements.

Estimate body fat percentage using the standardized US Navy MethodUS Navy Standard

Calculated Body Composition

Composition Metrics

Body Composition Ready

Provide your waist, neck, height, and hip (for females) circumferences to see estimated body fat ratio, muscle weights, and categories.

How to Take Measurements for Navy Method Accuracy

1. Neck MeasurementMeasure directly below the larynx (Adam's apple), wrapping the tape horizontal to the floor. Keep your shoulders relaxed and don't flare your neck.
2. Waist MeasurementMeasure horizontally around the abdomen, right at the navel (belly button) level for males, or at the narrowest natural waistline above the navel for females. Don't suck in!
3. Hips Measurement (Females)Wrap the tape measure horizontally around the widest part of the hips and gluteal cheeks. Make sure the tape is flat and level all the way around.

Methodology & Formula: US Navy Circumference Equation

Calculates body fat percentage using key circumference measurements in inches: • Men: BF% = 86.010 × log10(Waist - Neck) - 70.041 × log10(Height) + 36.76 • Women: BF% = 163.205 × log10(Waist + Hip - Neck) - 97.684 × log10(Height) - 78.387

Standard Reference Calculations

Adult Male Athlete

Inputs: Height: 70 in (177.8 cm), Neck: 15 in, Waist: 32 in
Output: Body Fat = 12.8% (Athletic Range)

Adult Female Builder

Inputs: Height: 65 in (165.1 cm), Neck: 13.5 in, Waist: 28 in, Hip: 36 in
Output: Body Fat = 22.1% (Fitness Range)

Frequently Asked Questions

Get answers to common queries based on clinical literature and fitness research.

Essential fat is 2-5% for men and 10-13% for women. Athletic ranges are typically 6-13% (men) and 14-20% (women). General fitness is 14-17% (men) and 21-24% (women). Over 25% for men and 32% for women is considered obese.

When measured correctly, the US Navy formula is surprisingly accurate, usually within 3-4% of DEXA scans, which are the clinical gold standard. Ensure the tape measurement is snug but not compressing the skin.

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