Body Fat Calculator
No InBody scan needed — estimate your body fat with just a tape measure.
Sex
Measure snugly without squeezing the skin: neck just below the larynx, waist at the navel (men) or narrowest point (women), hip at the widest point.
This looks like an unrealistic reading — recheck your measuring spots.
Estimated with the U.S. Navy circumference method (±3-4% vs DEXA). Treat it as a trend indicator, not a clinical measurement.
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How accurate is the U.S. Navy tape method?
For most people, the U.S. Navy circumference method is accurate to about ±3-4% body fat compared with a DEXA or InBody scan — good enough to track progress over weeks. Accuracy depends on measuring at the same spots each time with a snug, level tape. It is less reliable at the extremes (very lean athletes or high body fat), where a lab method like DEXA is better.
Where exactly do I measure neck, waist and hip?
Stand relaxed and keep the tape horizontal and snug without compressing the skin. Neck: just below the larynx (Adam's apple), sloping slightly down toward the front. Waist: at the navel for men, at the narrowest point for women. Hip (women only): around the widest part of the buttocks. Measure on bare skin after a normal exhale, and repeat each measurement twice for consistency.
What is a healthy body fat percentage?
Using ACE categories: for men, essential fat is 2-5%, athletes 6-13%, fitness 14-17%, average 18-24%, and obese 25%+. For women, essential fat is 10-13%, athletes 14-20%, fitness 21-24%, average 25-31%, and obese 32%+. Women naturally carry more essential fat for hormonal and reproductive health, so the healthy ranges are higher than for men.
Can my BMI be normal but my body fat high?
Yes — this is often called "skinny fat". BMI only uses height and weight, so someone with little muscle and more fat can have a normal BMI while their body fat percentage is high. Because this calculator measures actual girths and reports fat mass and lean body mass separately, it catches cases that a BMI calculator misses.
Is my body data sent to a server?
No. Every calculation runs entirely inside your browser; your measurements never leave your device. They are only saved to your browser's localStorage so the form is pre-filled on your next visit, and you can clear them anytime from your browser settings.