About Body Fat Calculator
Calculate body fat percentage using the standardized US Navy circumference equation for men and women. Computes fat mass, lean body mass (LBM), and categorizes body composition according to American Council on Exercise (ACE) standards.
Key Capabilities & Features
- Official US Navy circumference algorithms for men (neck, waist) and women (neck, waist, hip)
- Total Fat Mass and Lean Body Mass (LBM) breakdown in kilograms and pounds
- American Council on Exercise (ACE) category benchmarking: Essential, Athlete, Fitness, Average, Obese
- Interactive Metric and Imperial circumference unit toggles
How to Use Body Fat Calculator
Select Biological Sex
Choose male or female to apply the anatomically correct Navy formula.
Measure Circumferences
Measure your neck, waist (at navel or narrowest), and hips (for females) with a tape measure.
View Body Fat & Lean Mass
Review estimated body fat percentage and lean muscle mass.
Privacy & In-Browser Execution Guarantee
100% client-side calculation. Your data never leaves your browser.
Frequently Asked Questions
How accurate is the US Navy tape method?
When measurements are taken carefully with a flexible tape, the US Navy method typically correlates within 3-4% of DEXA and hydrostatic underwater weighing.
Where should men measure the waist?
Men should measure horizontally around the abdomen at the level of the navel (belly button) while relaxed.