What Is Your Body Fat Percentage?
Estimate body fat % using the US Navy circumference method. Enter your weight, height, waist, and neck measurements — no gym equipment needed.
The US Navy method gives body fat estimates within ±3–4% of DEXA scan accuracy — from just a tape measure.
±3–4%
Navy method accuracy vs DEXA scan (the gold standard)
28%
average body fat percentage for adult American males
40%
average body fat percentage for adult American females
Body fat: what the numbers mean
Measure consistently for tracking
Body fat measurements vary based on time of day, hydration, and measurement technique. For consistent tracking, always measure at the same time of day (morning, after using the toilet), with the same tape measure, relaxed posture, and using the same measurement landmarks. Changes over weeks matter — daily variation is noise.
Lean mass is more important than body fat
Two people can have the same body fat percentage but very different health and performance profiles if their lean mass differs. Focus on building and preserving lean mass (through resistance training and adequate protein) rather than obsessing over fat percentage alone.
More accurate methods exist
For the most accurate body fat measurement: DEXA scan ($50–$150) gives a full body composition breakdown including bone density. Hydrostatic weighing is also highly accurate. InBody or bioelectrical impedance scales are convenient but can be off by 5%+ depending on hydration levels.
How the Body Fat Calculator Works
US Navy formula (male): body fat % = 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76. All measurements in inches. Fat mass = weight × (body fat % ÷ 100). Lean mass = weight − fat mass.
This calculator uses the male Navy formula. For women, the formula also includes hip measurement: % = 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387. Take all measurements in a relaxed state, tape parallel to the floor, at the end of a normal exhale.