Body Fat Calculator

Estimate your body fat percentage using standard measurement methods.

Health

A Deeper Look at Body Composition

Body fat percentage can be a more accurate indicator of health than weight or BMI alone, as it distinguishes between fat mass and lean mass. This calculator uses the U.S. Navy formula, a circumference-based method, to provide a convenient estimate of your body fat percentage.

The U.S. Navy Formula Explained

This method uses gender, height, and circumference measurements to estimate body density, which is then used to calculate body fat percentage. The specific formulas are:

  • For Men: %Fat = 495 / (1.0324 - 0.19077 * log10(waist - neck) + 0.15456 * log10(height)) - 450
  • For Women: %Fat = 495 / (1.29579 - 0.35004 * log10(waist + hip - neck) + 0.22100 * log10(height)) - 450 (Note: Measurements are in centimeters for these specific equations)

How to Use the Calculator

  1. Select Gender and Units: Choose your gender and preferred measurement units (Metric or Imperial).
  2. Enter Measurements: Accurately measure your age, height, neck, and waist. For women, also measure your hips at the widest point.
  3. Calculate: The tool will provide your estimated body fat percentage.

Real-World Example

A 35-year-old male is 6 feet tall (72 inches), with a 36-inch waist and a 16-inch neck.

  • Using the calculator with these inputs would yield an estimated body fat percentage of around 18-20%, which falls into the 'Fitness' or 'Average' category for men.

Frequently Asked Questions (FAQ)

  • How accurate is this method? The U.S. Navy method is a reasonable estimation for the general population but can have a margin of error of ±3-4%. For more precise results, consider clinical methods like DXA scans.
  • What is a healthy body fat percentage? Healthy ranges vary by age and gender. For men, a healthy range is typically 10-20%, and for women, it's 20-30%. Athletes will often have lower percentages.
  • Why does this method use neck measurements? The neck measurement helps to estimate the amount of lean body mass, as it is less likely to store significant fat compared to the waist or hips. This provides a better overall picture of body composition.