Body Fat Calculator

A body fat calculator estimates your body fat percentage using the U.S. Navy circumference method. This method uses simple body measurements — height, neck, waist, and hip circumference — to provide a reliable estimate of body composition without expensive equipment.

Body fat percentage is a more meaningful indicator of health and fitness than weight alone. Two people at the same weight can have very different body compositions. Knowing your body fat percentage helps you set realistic fitness goals and track progress more accurately than scale weight.

This calculator categorizes your result into fitness levels: Essential Fat, Athletes, Fitness, Average, and Obese. These categories differ between men and women due to physiological differences in fat distribution and essential fat requirements.

1. Select your gender — Male or Female (affects the formula and categories).
2. Choose your unit system — Imperial (inches/lbs) or Metric (cm/kg).
3. Enter your weight — In pounds or kilograms.
4. Enter your height — Total height in inches or centimeters.
5. Measure your neck — Circumference at the narrowest point below the Adam's apple.
6. Measure your waist — Circumference at the navel (men) or narrowest point (women).
7. Measure your hips (women only) — Circumference at the widest point.
8. View results — See your estimated body fat %, fat mass, lean mass, and category.

U.S. Navy Method (measurements in cm):

Male: BF% = 495 / (1.0324 - 0.19077 × log10(waist - neck) + 0.15456 × log10(height)) - 450

Female: BF% = 495 / (1.29579 - 0.35004 × log10(waist + hip - neck) + 0.22100 × log10(height)) - 450

Fat Mass = Weight × (BF% / 100)

Lean Mass = Weight - Fat Mass