Body Fat Percentage Calculator

How This Calculator Works

This calculator uses the U.S. Navy body fat formula, which estimates body fat percentage based on circumference measurements. The formulas are:

For Men:
Body Fat % = 495 / (1.0324 - 0.19077 × log10(waist - neck) + 0.15456 × log10(height)) - 450

For Women:
Body Fat % = 495 / (1.29579 - 0.35004 × log10(waist + hip - neck) + 0.22100 × log10(height)) - 450

While not as accurate as methods like DEXA scans or hydrostatic weighing, the Navy method provides a reasonable estimate using simple measurements.

Understanding Body Fat Categories

Men:

• Essential Fat (2-5%): Minimum needed for basic physical and physiological health
• Athletes (6-13%): Typical for athletes, very lean
• Fitness (14-17%): Fit appearance with visible muscle definition
• Average (18-24%): Acceptable body fat for general health
• Obese (25%+): Increased health risks

Women:

• Essential Fat (10-13%): Minimum needed for basic health
• Athletes (14-20%): Typical for female athletes
• Fitness (21-24%): Fit appearance with muscle tone
• Average (25-31%): Acceptable for general health
• Obese (32%+): Increased health risks

Tips for Accurate Measurements

• Take measurements in the morning before eating or exercising
• Use a flexible measuring tape (cloth or plastic, not metal)
• Keep the tape snug but don't compress the skin
• Take measurements 2-3 times and use the average
• Stand naturally - don't flex or suck in your stomach
• Measure on bare skin for most accurate results
• Track measurements weekly to monitor changes over time

Limitations & Considerations

• The Navy method is an estimate - accuracy varies by individual
• More accurate for people with average body types
• May be less accurate for very lean or obese individuals
• Muscle distribution can affect accuracy
• Consider using multiple methods for best assessment
• Focus on trends over time rather than single measurements
• Body fat percentage is just one measure of health