About this body fat calculator
Two widely used estimates are provided: the US Navy circumference method, a log-regression model based on height, neck and waist (plus hip for women), and the BMI-based estimate (%BF = 1.20 × BMI + 0.23 × age − 10.8 × sex − 5.4) for a quick comparison. The Navy method is among the most accurate tape-only approaches.
The two methods can differ by several percentage points, so stick to one method when tracking trends over time. Everything is computed locally in your browser and no measurements are uploaded. Results are for general reference only and are not medical advice.