Body Fat Calculator
Estimate your body fat percentage using the US Navy circumference method — a proven, measurement-based approach.
How to measure correctly
Neck: Measure at the narrowest point, just below the larynx (Adam's apple). Keep the tape perpendicular to the neck.
Waist: For males, measure at the navel level. For females, measure at the narrowest point between ribs and hips.
Hips (female only): Measure at the widest point of the buttocks, keeping the tape horizontal.
Use a flexible measuring tape. Keep it snug but not compressing the skin. Take measurements first thing in the morning for consistency.
About Body Fat Calculator
This calculator estimates your body fat percentage using the US Navy circumference method, a widely validated technique based on body circumference measurements rather than skinfold calipers or expensive DEXA scans. By measuring your neck, waist, and hip (for females) circumferences and comparing them to your height, the formula provides a reliable estimate of your body composition.
US Navy Formula
Male: BF% = 86.01 × log10(waist - neck) - 70.04 × log10(height) + 36.76 | Female: BF% = 163.21 × log10(waist + hip - neck) - 97.68 × log10(height) - 78.39
Fat Mass & Lean Mass
See how much of your total body weight is fat mass versus lean body mass in both pounds and kilograms.
Category Classification
Your result is classified into Essential Fat, Athlete, Fitness, Average, or Obese ranges for easy interpretation.
Measurement Guides
Built-in instructions show you exactly where and how to take each measurement for the most accurate results.