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Free Body Fat Calculator Online

Calculate your body fat percentage using the US Navy method. More accurate than BMI for assessing body composition and fitness levels based on body circumference measurements.

Calculate Body Fat Percentage

Body Fat Percentage

US Navy Body Fat Formula

The US Navy method estimates body fat percentage using circumference measurements:

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

This method is widely used by military and fitness professionals for body composition assessment.

How to Measure for Accuracy

Measurement Tips

Neck: Measure around neck at the narrowest point, just below the Adam's apple
Waist: Measure around waist at navel level (men) or narrowest point (women)
Hips (Women): Measure around the widest part of hips/buttocks
Height: Measure without shoes, standing straight
Consistency: Take measurements at same time of day for tracking

Example Calculation

Example: Male

Height: 180 cm
Weight: 80 kg
Neck: 38 cm
Waist: 88 cm

Result: Approximately 18-20% body fat (Fitness category)

Body Fat Percentage Categories

Men

Essential Fat: 2-5% - Minimum for survival
Athletes: 6-13% - Typical for athletes
Fitness: 14-17% - Fit and healthy
Average: 18-24% - Average for men
Obese: 25%+ - Health risks increase

Women

Essential Fat: 10-13% - Minimum for survival
Athletes: 14-20% - Typical for athletes
Fitness: 21-24% - Fit and healthy
Average: 25-31% - Average for women
Obese: 32%+ - Health risks increase

Frequently Asked Questions

Q: Is body fat percentage more accurate than BMI?

A: Yes, body fat percentage provides a more accurate assessment of body composition because it distinguishes between fat and lean mass. BMI doesn't account for muscle mass, so athletes may have high BMI but low body fat.

Q: How often should I measure body fat?

A: Monthly measurements are sufficient for tracking progress. Body composition changes gradually, so more frequent measurements aren't necessary and may be discouraging.

Q: What's a healthy body fat percentage?

A: For men, 10-20% is generally healthy; for women, 18-28%. However, ideal ranges vary by age, fitness level, and individual goals. Athletes typically have lower percentages, while some body fat is essential for health.

⚠️ Health Disclaimer

This calculator provides estimates for educational purposes only. It does not provide medical diagnosis or replace professional medical advice. Body fat calculations have margins of error. Always consult qualified healthcare professionals for health concerns, medical conditions, or before starting diet or exercise programs.