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    Body Fat CalculatorFree Online Health Tool

    Body Fat Calculator is a free online health tool. Estimate your body fat percentage using the U.S. Navy circumference method. Free body composition calculator.

    Input

    Values

    Action

    Calculate result

    Output

    View answer

    Runs in your browser when supported. No signup required.

    Your Measurements
    Enter your body measurements (in cm)
    Your Body Fat
    Estimated body composition

    Body Fat Percentage

    16.9%

    Fitness

    Body Fat Categories (Men):

    Essential Fat: 2-5%

    Athletes: 6-13%

    Fitness: 14-17%

    Average: 18-24%

    Obese: >25%

    100% Private100% Private
    InstantInstant
    Any DeviceAny Device
    Free ForeverFree Forever
    How to useHow to use & Tips

    Steps

    1. 1Select the formula for male or female measurements
    2. 2Measure your height without shoes and keep every value in centimeters
    3. 3Measure the waist or abdomen at the location described in the guide below
    4. 4Measure the neck just below the larynx without compressing the skin
    5. 5For the female formula, also measure around the widest part of the hips
    6. 6Repeat each measurement, enter the averages, and use the result as an estimate

    Use Cases

    • -Track a circumference-based estimate under consistent conditions
    • -Compare a multi-week trend during a training or nutrition program
    • -Add body-composition context alongside weight and waist measurements
    • -Prepare questions before discussing body composition with a qualified professional

    About Body Fat Calculator

    Everything you need to know about this tool and how to get the most out of it.

    What is Body Fat Calculator?

    What is Body Fat Calculator?

    A Body Fat Calculator estimates your body fat percentage using the U.S. Navy circumference method. It uses body measurements (height, waist, neck, and hip for women) to estimate the percentage of your body weight that is fat.
    How Body Fat Calculator Works

    How Body Fat Calculator Works

    The U.S. Navy method estimates body density from circumference ratios and then converts that estimate to body fat percentage. This calculator expects centimeters throughout. Men enter height, abdomen/waist, and neck; women also enter hip circumference. Mixing inches and centimeters produces an invalid result.
    Why Use Body Fat Calculator?

    Why Use Body Fat Calculator?

    Body fat percentage can add context that body weight alone cannot provide, but circumference estimates should be used for trends rather than diagnosis. Measure under similar conditions and compare changes over several weeks instead of reacting to one reading.
    Tips

    Tips & Best Practices

    • 1Use a flexible tape held level and snug without compressing the skin
    • 2Measure at the same time of day and repeat each site two or three times
    • 3Keep every measurement in centimeters
    • 4Stop and check the entries if waist is not greater than neck
    • 5Use a clinician or validated laboratory method when an accurate assessment affects medical decisions
    How to take the measurements

    How to take the measurements

    Stand upright and relaxed. Measure height without shoes. For men, measure the abdomen horizontally at navel level; for women, measure the natural waist at its narrowest point and hips around the widest part of the buttocks. Measure neck just below the larynx with the tape sloping slightly downward toward the front. Exhale normally, do not pull the stomach in, and record each value to the nearest 0.5 cm.
    How to interpret the result

    How to interpret the result

    The displayed category is a broad reference band, not a medical diagnosis. Hydration, tape placement, body shape, recent food intake, and measurement technique can shift the estimate. The most useful comparison uses the same tape, locations, and conditions over time. If the result appears implausible, retake every measurement before drawing conclusions.
    Limits of the Navy circumference method

    Limits of the Navy circumference method

    Circumference formulas estimate body composition from population averages and can be less representative for very muscular people, older adults, pregnant people, and body shapes unlike the reference population. DEXA, air-displacement plethysmography, and professionally administered skinfold or hydrostatic tests may provide more detailed assessment. Ask a qualified healthcare professional about unexplained weight change or health concerns.

    Frequently Asked Questions