Body Fat Percentage Calculator
Estimate body fat and lean mass from height and a few circumference measurements — the U.S. Navy method.
The Navy formula uses different measurement points by sex — this only affects which inputs are needed, not a health judgment.
Measured just below the larynx.
Measured at the navel.
About 83.1% of your body weight is estimated to be lean mass (muscle, bone, organs, and water) rather than fat.
An estimate, not a lab measurement. The circumference method is accurate to within a few percentage points for most people but can be less reliable for very lean or very heavy individuals. For a precise reading, ask a healthcare provider about DEXA scanning or hydrostatic weighing.
Log-based circumference formula
Common questions
It's generally accurate to within about 3–4 percentage points of more precise methods like DEXA scanning for most body types, which is why the U.S. Navy still uses it for routine body composition checks. It tends to be less reliable at the extremes — very lean athletes or people carrying weight in unusual distributions.