The Body Fat Percentage Calculator estimates the proportion of your body weight that is fat mass using body measurements. Unlike BMI, it distinguishes between fat and lean mass โ€” giving a clearer picture of body composition and health risk.

Body Fat Percentage Calculator

Estimate your body fat percentage using the U.S. Navy method.

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How to Use This Calculator

  1. Select your gender โ€” men and women store fat differently, so separate formulas apply.
  2. Enter your weight, height, and key circumference measurements (waist, neck, and for women, hip).
  3. Click Calculate.

Body Fat Percentage Categories

Category Women Men
Essential Fat 10โ€“13% 2โ€“5%
Athletes 14โ€“20% 6โ€“13%
Fitness 21โ€“24% 14โ€“17%
Average 25โ€“31% 18โ€“24%
Obese 32%+ 25%+

Why Body Fat % Is More Informative Than BMI

BMI only measures weight relative to height โ€” it cannot distinguish between muscle and fat. A muscular athlete may have a BMI classified as “overweight” while having very low body fat. Conversely, a sedentary person with a normal BMI may have excess fat (“skinny fat”) with associated health risks.

Body fat percentage, combined with waist circumference, gives a far better picture of metabolic health risk. Research consistently shows that abdominal (visceral) fat โ€” not total weight โ€” is the strongest predictor of cardiovascular disease and type 2 diabetes.

How to Measure Accurately

  • Waist: Measure at the narrowest point, about 1 inch above the belly button. Don’t suck in.
  • Neck: Measure just below the larynx (Adam’s apple), sloping slightly downward at the front.
  • Hip (women only): Measure at the widest point of the buttocks.
  • Measure in the morning before eating, using a flexible tape measure.

Frequently Asked Questions

How accurate is this measurement method?

The US Navy circumference method used here is within 3โ€“4% accuracy for most people โ€” comparable to skinfold calipers. DEXA scans and hydrostatic weighing are more accurate (ยฑ1โ€“2%) but require specialized equipment. For tracking progress over time, consistency of measurement technique matters more than absolute accuracy.

What body fat percentage should I aim for?

For health and longevity, the fitness range (14โ€“20% for women, 14โ€“17% for men) is ideal for most people. Achieving athlete-level body fat requires significant dietary restriction and is not necessary for good health.

How it works

The US Navy method uses circumference measurements to estimate body fat. For men: body density is calculated from neck and waist measurements relative to height, then converted to body fat % using the Siri equation. For women, the hip measurement is added. The formula was developed through research on military personnel.

Formula

Men: BF% = 86.010ร—log10(waistโˆ’neck) โˆ’ 70.041ร—log10(height) + 36.76. Women: BF% = 163.205ร—log10(waist+hipโˆ’neck) โˆ’ 97.684ร—log10(height) โˆ’ 78.387