This Body Fat calculator estimates your total body fat percentage using precise measurements. For the International System of Units (SI), select the “Metric Units” tab. For accuracy, measure to the nearest ¼ inch (0.5 cm). The calculator applies the U.S. Navy method and provides an estimate based on the BMI method—both are detailed below.

Body Fat Reference Guide

How to Use the Body Fat Calculator

Unlike BMI, body fat percentage tells you exactly how much of your weight is fat versus muscle, bone, and water. This calculator uses the U.S. Navy circumference method, a well-validated approach that requires only a tape measure, no expensive equipment.

Choose your unit system at the top US Units (inches and pounds) or Metric (centimeters and kilograms).

Select your gender. The male and female formulas are different because fat distribution differs between sexes. Females include a hip measurement; males do not.

Enter your measurements. Here’s how to measure each one correctly:

• Neck: Measure just below the larynx (Adam’s apple), keeping the tape horizontal.
• Waist: Measure at the narrowest point, typically just above the navel. Don’t suck in.
• Hip (females only): Measure at the widest point around the buttocks.

Enter your age and weight. These are used to calculate fat mass, lean mass, and your ideal body fat for your age group.

Click Calculate. Your results include your body fat percentage, your fitness category (Essential, Athlete, Fitness, Acceptable, or Obese), your fat mass and lean mass in kilograms, your ideal body fat percentage for your age, how much fat you’d need to lose to reach that ideal, and a BMI-method cross-check.

Enable Progress Tracking to save your results over time and watch trends. A shrinking body fat percentage while weight stays stable is a sign that you’re gaining muscle, which is exactly what most people are training for.

Note on measurement accuracy: Take measurements in the morning before eating or drinking for the most consistent results. Measure in the same spot each time and use a flexible tape measure, not a ruler.

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