Body Fat Calculator
Estimate your body fat percentage using the US Navy method.
US Navy circumference method. Accurate to within ~3–4 percentage points for most people.
About the Body Fat Calculator
Body fat percentage tells you more about your health than weight alone, because it separates fat mass from muscle and bone. The AlarmDaddy Body Fat Calculator uses the US Navy circumference method — a tape-measure-only approach that needs no special equipment and is surprisingly accurate for most people.
Enter your sex, height, neck and waist measurements (and hip measurement for women). The calculator estimates your body fat percentage and places you in a category from essential fat through athletic, fit, average, and obese. Track it over weeks rather than days, and use it alongside BMI for a complete view — two people with the same BMI can have very different body fat.
How to use this calculator
- 1Select your sex.
- 2Enter your height.
- 3Measure and enter your neck and waist circumference (and hip, for women).
- 4Read your estimated body fat percentage and fitness category.
The formula
The US Navy formula derives body-fat percentage from body circumferences. For men it uses waist and neck; for women it adds the hip measurement. Each is measured against height using a logarithmic equation. It is a validated estimate, not a lab measurement like a DEXA scan.