Body Fat Calculator
Determine your body fat percentage using Navy, BMI, and Skinfold methods. Track your fitness progress.
A body fat calculator estimates the percentage of your body weight that is fat tissue. Unlike BMI, body fat percentage accounts for muscle mass and provides a more accurate picture of body composition and health risk.
Examples
Male, Navy Method
Female, Navy Method
Frequently Asked Questions
Which method is most accurate?
What is essential fat?
Key Terms
- Essential Fat
- The minimum amount of fat necessary for normal physiological function, higher in women due to reproductive needs.
- Visceral Fat
- Fat stored around internal organs in the abdominal cavity, strongly linked to metabolic disease risk.
- Lean Body Mass
- Total body weight minus fat weight, including muscle, bone, water, and organs.
References
- Body Composition — American Council on Exercise (ACE)
Quick Tips
- •Measure at the same time of day under similar conditions for consistent tracking.
- •Focus on trends over time rather than any single measurement.
- •Essential fat is 2-5% for men and 10-13% for women — going below these levels is dangerous.
- •Combine body fat measurements with strength benchmarks for a complete fitness picture.
A body fat calculator estimates the percentage of your body weight that is fat tissue. Unlike BMI, body fat percentage accounts for muscle mass and provides a more accurate picture of body composition and health risk.
How to Use This Calculator
Select a measurement method (US Navy is common and requires only a few measurements). Enter the measurements it asks for (e.g. waist, neck, height, and sometimes hip). Click Calculate to see your estimated body fat percentage and category. For consistent results, measure under similar conditions (e.g. morning, before eating).
Understanding the Formula
Uses the U.S. Navy Circumference method or Jackson-Pollock 3-site Skinfold formula to estimate body density and fat percentage.
Examples
Male, Navy Method
A 30-year-old male, 5'10", 180 lbs, with a 36-inch waist and 15-inch neck yields approximately 18.5% body fat (Fitness category).
Female, Navy Method
A 28-year-old female, 5'5", 140 lbs, with a 30-inch waist, 13-inch neck, and 38-inch hips yields approximately 25.2% body fat (Fitness category).
Frequently Asked Questions
Which method is most accurate?
DEXA scans are gold standard. Of these tools, US Navy and Skinfold are good; BMI is only an estimate.
What is essential fat?
The minimum fat needed for survival (2-5% men, 10-13% women).
Assumptions & Limitations
- Skinfold and circumference-based estimates have a margin of error of 3-5%.
- Results vary by measurement method — navy method, skinfold calipers, and BIA give different readings.
- Hydration levels, recent meals, and time of day can affect measurement accuracy.
Key Terms
- Essential Fat
- The minimum amount of fat necessary for normal physiological function, higher in women due to reproductive needs.
- Visceral Fat
- Fat stored around internal organs in the abdominal cavity, strongly linked to metabolic disease risk.
- Lean Body Mass
- Total body weight minus fat weight, including muscle, bone, water, and organs.
References
- Body Composition — American Council on Exercise (ACE)