This calculator uses the U.S. Navy circumference method, a validated formula that estimates body fat percentage from simple tape-measure measurements — no expensive equipment required.
This calculator uses the U.S. Navy circumference method, a validated formula that estimates body fat percentage from simple tape-measure measurements — no expensive equipment required. This calculator draws on peer-reviewed, industry-standard formulas used by fitness professionals, dietitians and clinicians worldwide, translated into a fast, easy-to-use browser tool.
Tracking metrics like this over time — rather than relying on a single reading — gives you a much clearer picture of trends in your health and fitness journey. Use this tool regularly alongside our other calculators for a fuller picture of your overall wellbeing.
It's typically accurate within 3-4% of body fat compared to DEXA scans for most body types, making it one of the best at-home estimation methods.
Measure your neck just below the larynx, and your waist at the narrowest point (or at navel level if no natural waist is visible). Keep the tape snug but not tight.
The formula for women includes hip circumference because fat distribution patterns differ from men, improving estimation accuracy.