Body Fat Calculator
Calculate your body fat percentage and understand body composition
What is Body Fat Percentage?
Body Fat Percentage is the proportion of fat weight to total body weight, an important indicator of body composition. Unlike BMI, body fat percentage accurately reflects actual fat content and distinguishes between fat and muscle. This tool supports the US Navy circumference method and BMI estimation method to help you understand your body fat level.
How to Use
- Select the calculation method (Navy is more precise, BMI is simpler)
- Select gender, unit system, and enter age, height, weight and other data
- Click calculate to see your body fat percentage, fat mass and lean mass
Calculation Methods
US Navy Circumference Method
Calculates body fat percentage using neck circumference, waist circumference (hip for women), and height. Developed by the US military with higher accuracy. Requires a tape measure for body measurements. Best measured in the morning on an empty stomach with natural breathing.
BMI Estimation Method
Estimates body fat using the Deurenberg formula based on BMI, age, and gender: BFP = 1.20 × BMI + 0.23 × Age - 10.8 × Gender - 5.4. This method is simpler but less accurate, suitable for quick estimates.
FAQ
Q: What is a normal body fat percentage?
A: Normal body fat is generally 10-20% for men and 18-28% for women. Athletes typically have lower levels (6-13% for men, 14-20% for women). Normal ranges increase slightly with age.
Q: Which is more accurate, Navy or BMI method?
A: The Navy method is generally more accurate as it directly measures body circumferences, better distinguishing fat from muscle. The BMI method estimates based on weight and height, which may overestimate for muscular individuals. The Navy method is recommended.
Q: Is lower body fat always better?
A: No. Very low body fat (men <6%, women <14%) can affect hormone levels, immune function, and temperature regulation. Maintaining adequate body fat is most important for health.
Q: How to accurately measure neck and waist?
A: Neck: Measure horizontally at the narrowest point below the Adam's apple. Waist: Measure horizontally at the narrowest point above the navel. Breathe naturally, don't suck in your stomach. The tape should be snug but not tight. Take 2-3 measurements and average them.