What is body fat percentage and why does it matter?

Body fat percentage is the proportion of fat tissue compared to total body weight. It's a better indicator of health and fitness than weight alone because it distinguishes between fat mass and lean mass (muscle, bone, organs). Healthy body fat levels vary by gender and age, but maintaining them reduces risk of heart disease, diabetes, and other conditions.

How accurate is the US Navy Method?

The US Navy Method is considered reasonably accurate, typically within 3-4% of results from more advanced methods like DEXA scans. It's most accurate for people with typical body proportions. Athletes with unusual muscle distribution or those with very high or low body fat may see less accurate results.

What are healthy body fat ranges for men and women?

For men: Essential fat is 2-5%, Athletes 6-13%, Fitness 14-17%, Average 18-24%, and Obese is 25%+. For women: Essential fat is 10-13%, Athletes 14-20%, Fitness 21-24%, Average 25-31%, and Obese is 32%+. Women naturally carry more body fat due to hormonal and reproductive factors.

How do I measure my waist and neck correctly?

For neck: Measure at the narrowest point, just below the larynx (Adam's apple), keeping the tape level. For waist: Measure at the navel for men, or at the narrowest point for women. For hips (women only): Measure at the widest point of the buttocks. Keep the tape snug but not tight, and measure on bare skin.

Body Fat Calculator

Calculate your body fat percentage using the US Navy Method. Get accurate fat mass and lean mass measurements based on body circumference.

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Age

Gender

Male

Female

Height

ft

in

Weightlbs

Body Measurements

Neck Circumference

in

Measure at the narrowest point below the Adam's apple

Waist Circumference

in

Measure at the navel (belly button)

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Last updated: January 2026 • Built with care by iForge Apps

How to use this tool

1

Select your preferred unit system (Imperial or Metric)

2

Enter your age and select your gender

3

Enter your height in feet/inches or centimeters

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