Body Fat % Calculator
Estimate your body fat percentage using the US Navy tape-measure method.
Estimated body fat
This calculator provides a general estimate for informational purposes only. It is not a medical device and does not provide medical advice or diagnosis. Always consult a qualified healthcare professional about your individual health circumstances.
Frequently Asked Questions
How does the tape-measure method work?
It uses your height and simple circumference measurements (neck, waist, and hip for women) in a formula developed by the US Navy in 1984, which correlates closely with more precise methods like hydrostatic weighing.
How accurate is this method?
Studies comparing it to hydrostatic (underwater) weighing — a gold-standard body composition measurement — have found it can come reasonably close for many people, though individual accuracy varies and it tends to be less reliable at the very lean or very high end of the range. It's a convenient estimate, not a clinical-grade measurement.
How do I measure correctly?
Measure your neck just below the larynx. For waist: men should measure at the level of the navel; women should measure at the narrowest point of the torso, between the sternum and navel. For hip (women only), measure at the widest point. Take all measurements after a normal exhale, with the tape snug but not compressing the skin — using the wrong waist location is the most common source of error.
Want lab-grade insight to go with this estimate?
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