Free Body Fat Calculator

Calculate your body fat percentage using the accurate US Navy method or simpler BMI-based estimation. Get your fat mass and lean mass breakdown.

Body Measurements

Measure at navel level

Measure below larynx

Body Fat Categories (Men)

Essential Fat
2-5%
Athletes
6-13%
Fitness
14-17%
Average
18-24%
Obese
25-100+%

Essential fat is the minimum required for basic physical and physiological health.

How to Use the Body Fat Calculator

Choose Your Calculation Method

Select either the US Navy method (more accurate, requires body measurements) or the BMI-based method (simpler, uses only height and weight). The US Navy method is recommended for better accuracy.

Enter Your Basic Information

Input your biological sex (male or female), weight, and height. Select metric (kg/cm) or imperial (lbs/inches) units based on your preference.

Take Body Measurements (US Navy Method)

Measure your waist at the navel (belly button) level while relaxed. Measure your neck just below the Adam's apple. Women also need to measure hips at the widest point. Use a flexible tape measure for accuracy.

Review Your Body Composition Results

View your body fat percentage, fat mass, and lean mass. Compare your results to the category guidelines (essential, athletic, fitness, average, or obese) to understand where you stand and set fitness goals.

Pro tip: Your data is processed entirely in your browser. Nothing is sent to any server, ensuring complete privacy.

Understanding Body Fat

Body fat percentage is a more accurate measure of fitness than weight or BMI alone. It tells you what proportion of your body is fat versus lean tissue (muscle, bone, organs, water). Two people with the same weight can have very different body compositions.

Why Body Fat Matters

  • Health Risk: Excess body fat, especially around the abdomen, increases risk of heart disease and diabetes
  • Fitness Tracking: Monitor actual fat loss vs muscle gain during training
  • Athletic Performance: Lower body fat generally improves performance in most sports
  • Metabolism: More lean mass means higher resting metabolic rate

Frequently Asked Questions

What is body fat percentage?

Body fat percentage is the proportion of fat tissue in your body compared to your total body weight. It includes both essential fat (needed for normal body functions) and storage fat (energy reserves). Body fat percentage is a better indicator of health and fitness than weight alone.

What is the US Navy body fat formula?

The US Navy method calculates body fat using circumference measurements of the waist, neck, and hips (for women), along with height. It was developed by the US Navy as a reliable field method for estimating body composition without specialized equipment.

What is a healthy body fat percentage?

Healthy body fat ranges vary by gender. For men: 6-24% is generally healthy, with 14-17% being fitness level. For women: 14-31% is healthy, with 21-24% being fitness level. Athletes may have lower percentages. Essential fat (minimum for health) is 2-5% for men and 10-13% for women.

How accurate is body fat calculation?

The US Navy method is generally accurate within 3-4% of actual body fat. BMI-based estimates are less accurate but require fewer measurements. For the most accurate results, consider DEXA scans, hydrostatic weighing, or professional body composition analysis.

Where should I measure my waist?

For the US Navy method, measure your waist at the navel (belly button) level while standing relaxed. Do not suck in your stomach. For the neck, measure just below the larynx (Adam's apple). For hips (women only), measure at the widest point.

How often should I check my body fat?

For tracking fitness progress, measure body fat every 2-4 weeks under consistent conditions (same time of day, same hydration level). Changes in body composition take time, so more frequent measurements may not show meaningful differences.