Body Fat Calculator

The Body Fat Calculator estimates your body fat percentage using the U.S. Navy circumference method, which requires only a tape measure and a few basic measurements.

The U.S. Navy method

This method estimates body fat percentage from circumference measurements using logarithmic formulas developed by the U.S. Navy for fitness assessments:

Men: BF% = 495 / (1.0324 − 0.19077×log10(waist−neck) + 0.15456×log10(height)) − 450 Women: BF% = 495 / (1.29579 − 0.35004×log10(waist+hip−neck) + 0.22100×log10(height)) − 450

All measurements are in inches. For best accuracy, measure your neck just below the larynx, your waist at the navel, and (for women) your hips at their widest point.

Example: A man who is 69" tall with a 15" neck and 34" waist has an estimated body fat of about 11.5%, in the "Athletic" category.

Accuracy

The Navy method is reasonably accurate for most people (within a few percentage points) but can be less reliable for very lean or very heavy individuals. For a broader screening tool, see our BMI Calculator.

Related Calculators