1. What is Body Fat Percentage?

The body fat percentage is the total mass of fat divided by total body mass. For bodybuilders, this is a more accurate measure than BMI since it accounts for muscle mass. The US Navy method uses circumference measurements to estimate body fat.

2. How Does the Calculator Work?

The calculator uses the US Navy body fat formula:

For women, the formula is adjusted:

Where:

• \( \text{waist} \) — Waist circumference at navel (cm)
• \( \text{neck} \) — Neck circumference (cm)
• \( \text{height} \) — Height (cm)
• \( \log \) — Logarithm base 10

3. Importance for Bodybuilders

Details: Bodybuilders often have high BMI scores due to muscle mass, making body fat percentage a better indicator of actual fitness level and body composition.

4. Using the Calculator

Tips: Measure waist at navel level and neck at narrowest point. All measurements should be in centimeters. For most accurate results, take measurements in the morning before eating.

5. Frequently Asked Questions (FAQ)

Q1: Why use this instead of BMI for bodybuilders?
A: BMI doesn't distinguish between muscle and fat, often classifying muscular individuals as overweight or obese.

Q2: What are ideal body fat percentages?
A: For men: 6-24% (athletes 6-13%), for women: 16-30% (athletes 14-20%).

Q3: How accurate is this method?
A: Within 3-5% of more precise methods like DEXA scans when measurements are taken properly.

Q4: How often should I measure?
A: Every 2-4 weeks to track progress, as daily fluctuations are normal.

Q5: Should I flex when measuring?
A: No, measurements should be taken with muscles relaxed for consistency.