Calculate your body fat percentage using the US Navy method. Get accurate body fat estimates based on your measurements and understand your body composition.
Enter your age in years
Enter your height in centimeters
Measure your neck at the narrowest point
Measure your waist at the navel level
Body fat percentage is a more accurate indicator of health and fitness than weight alone. While BMI provides a general assessment, body fat percentage reveals the actual composition of your body—distinguishing between muscle and fat. Understanding your body fat percentage, how it's calculated, what healthy ranges are, and how to improve it is essential for achieving fitness goals and maintaining optimal health. Our comprehensive body fat calculator guide uses the proven US Navy method to help you accurately estimate your body fat percentage and understand what it means for your health and fitness journey.
Body fat percentage is the proportion of your total body weight that consists of fat tissue. Unlike BMI, which only considers height and weight, body fat percentage accounts for body composition—the ratio of fat to lean mass (muscle, bone, organs, water). This makes it a superior metric for assessing health and fitness, as two people with the same BMI can have very different body compositions and health profiles.
Body fat percentage provides crucial insights into your health that weight and BMI cannot. Excess body fat, especially visceral fat around organs, is associated with increased risk of cardiovascular disease, type 2 diabetes, certain cancers, and metabolic disorders. Conversely, too little body fat can indicate malnutrition, hormonal issues, or other health problems. Understanding your body fat percentage helps you set realistic fitness goals, track progress more accurately, and make informed decisions about diet and exercise.
Our calculator uses the US Navy method, a validated formula developed by the US Navy to estimate body fat percentage using simple body measurements. This method is highly accurate (within 3-4% of more expensive methods like DEXA scans) and requires only a measuring tape, making it accessible and practical for regular use.
The US Navy method uses measurements of height, neck circumference, waist circumference, and (for women) hip circumference, along with age and gender, to estimate body fat percentage. The formulas differ for men and women:
Body Fat % = 86.010 × log₁₀(waist - neck) - 70.041 × log₁₀(height) + 36.76
Body Fat % = 163.205 × log₁₀(waist + hip - neck) - 97.684 × log₁₀(height) - 78.387
These formulas account for the different fat distribution patterns between men and women, with women typically storing more fat in the hips and thighs.
Accurate measurements are crucial for reliable body fat estimates. Here's how to measure correctly:
Measure your height without shoes, standing straight against a wall. Use a metric system (centimeters) or imperial system (feet and inches) consistently throughout all measurements.
Measure your neck at its narrowest point, typically just below the larynx (Adam's apple). Keep the tape horizontal and snug but not tight. Avoid tilting your head up or down.
For men: Measure at the navel level, keeping the tape horizontal and parallel to the floor. Don't suck in your stomach or push it out.
For women: Measure at the narrowest point of your waist, typically above the navel. Keep the tape horizontal and snug.
Measure at the widest point of your hips, typically around the buttocks. Keep the tape horizontal and parallel to the floor. This measurement is only needed for women.
Note that women naturally have higher body fat percentages than men due to biological differences, including reproductive functions and hormonal differences.
Essential fat is the minimum amount of body fat necessary for normal physiological function. Going below essential fat levels can cause serious health problems, including hormonal imbalances, reproductive issues, and organ dysfunction. This level is typically only seen in competitive bodybuilders and is not recommended for long-term health.
The athletic range represents very low body fat with high muscle mass. This level is typical of competitive athletes and requires strict diet and training. While impressive, maintaining this level long-term can be challenging and may not be necessary for general health.
The fitness range represents a healthy balance of low body fat and good muscle mass. This is an excellent goal for most people seeking optimal health and fitness. It's achievable with consistent exercise and proper nutrition.
The average range is typical for most adults and is generally acceptable for health, though reducing body fat within this range can provide health benefits. If you're in this range, you're not necessarily unhealthy, but improving body composition can enhance health and fitness.
Body fat percentages in the obese range are associated with increased health risks, including cardiovascular disease, type 2 diabetes, and metabolic disorders. Reducing body fat through diet and exercise is recommended for health improvement.
Body fat percentage tends to increase with age due to decreased muscle mass, slower metabolism, and hormonal changes. However, regular exercise and proper nutrition can help maintain healthy body fat levels throughout life.
Women naturally have higher body fat percentages than men due to biological differences. Essential fat requirements are higher for women (10-13% vs. 2-5% for men) due to reproductive functions and hormonal differences.
Genetics influence where you store fat, how easily you gain or lose fat, and your natural body composition. While genetics play a role, lifestyle factors (diet and exercise) have a much larger impact on body fat percentage.
Diet, exercise, sleep, stress, and other lifestyle factors significantly impact body fat percentage. Regular exercise, especially strength training, increases muscle mass and reduces body fat. Proper nutrition with appropriate calorie balance is essential for managing body fat.
Our body fat calculator makes it easy to estimate your body fat percentage using the proven US Navy method. Here's how to use it:
Building muscle through strength training increases your metabolic rate and improves body composition. More muscle means higher calorie burn at rest and better body fat percentage, even if your weight doesn't change significantly.
Cardio exercise burns calories and helps create the calorie deficit needed for fat loss. Combine cardio with strength training for optimal body composition improvements.
Nutrition is crucial for body fat management. Focus on whole foods, adequate protein (to preserve muscle during fat loss), appropriate calorie balance, and nutrient-dense foods. Avoid extreme diets that cause muscle loss along with fat loss.
Improving body fat percentage takes time and consistency. Sustainable changes to diet and exercise habits produce lasting results, while quick fixes often lead to rebound.
While the US Navy method is highly accurate, it has limitations:
For the most accurate measurements, consider professional methods like DEXA scans, hydrostatic weighing, or BodPod, though these are more expensive and less accessible.
While BMI is a useful screening tool, body fat percentage provides more accurate health assessment. BMI doesn't distinguish between muscle and fat, so a muscular athlete might have a high BMI but low body fat. Body fat percentage accounts for body composition, making it superior for fitness and health assessment.
If your body fat percentage is in the obese range or you're concerned about your body composition, consult with healthcare professionals. They can provide comprehensive assessments, help you set realistic goals, and guide you toward safe and effective strategies for improving body composition. Registered dietitians, certified personal trainers, and healthcare providers can provide personalized guidance based on your individual needs and health status.
Understanding your body fat percentage is a valuable tool for assessing health and tracking fitness progress. Our body fat calculator uses the proven US Navy method to provide accurate estimates based on simple measurements. Remember that body fat percentage is just one health metric—overall health involves many factors including diet, exercise, sleep, stress management, and mental health. Use our calculator to track your progress, but focus on sustainable lifestyle changes rather than extreme measures. With consistent effort, proper nutrition, and regular exercise, you can achieve and maintain a healthy body fat percentage that supports your long-term health and fitness goals.
Body fat percentage is calculated using the US Navy method, which uses measurements of height, neck, waist (and hip for women) along with age and gender to estimate body fat percentage. This method provides a reliable estimate without requiring specialized equipment.
For men, a healthy body fat percentage is typically 10-20%, with 6-13% considered athletic and 2-5% essential. For women, healthy ranges are 18-28%, with 14-20% considered athletic and 10-13% essential. These ranges vary based on age and individual factors.
The US Navy body fat calculator provides a good estimate (within 3-4% accuracy) for most people. However, accuracy can vary based on body type, age, and fitness level. For the most accurate measurement, consider DEXA scan or hydrostatic weighing.
Measure your neck at the narrowest point (usually just below the larynx). Measure your waist at the navel level for men, or at the narrowest point for women. For women, also measure hips at the widest point. Take measurements in the morning before eating for best accuracy.