Body Fat Calculator

Estimate body fat percentage using the U.S. Navy method. Enter neck, waist, and height (plus hip for women). Choose US or metric units.

Your Measurements

Tips: measure at the **narrowest neck**, **widest waist** (at navel), and **widest hip** (women).

Results

Body Fat
14.5%
U.S. Navy method
Category
Fitness
ACE standard
Scale shown ~2–45% body fat.

Mass Breakdown

Fat Mass
10 kg
22 lb
Lean Mass
60 kg
132 lb
ACE CategoryMenWomen
Essential fat2–5%10–13%
Athletes6–13%14–20%
Fitness14–17%21–24%
Acceptable18–24%25–31%
Obese≥ 25%≥ 32%

This method estimates body fat from circumferences and height. Results may differ from DEXA, hydrostatic weighing, or calipers. Use consistent measuring technique for best comparisons.

Estimate your body fat percentage with our free body fat calculator using the U.S. Navy method, one of the most accessible and widely used body composition estimation techniques. Simply enter a few body measurements to get your result.

How Body Fat Percentage Is Calculated

This calculator uses the U.S. Navy circumference method, which estimates body fat using measurements of the neck, waist, and (for women) hip circumference, combined with height.

The formula differs slightly for men and women due to different fat distribution patterns, using logarithmic calculations based on these circumference measurements.

How to Use This Calculator

  1. Select your gender
  2. Enter your height
  3. Enter your neck circumference
  4. Enter your waist circumference (and hip circumference, if female)
  5. Click Calculate to view your estimated body fat percentage

Frequently Asked Questions

How accurate is the Navy method?

The Navy method is reasonably accurate for most people (typically within 3-4% of more precise methods like DEXA scans).

What is a healthy body fat percentage?

For men, 10-20% is generally considered healthy/athletic range. For women, 18-28% is typical.

Why do men and women have different formulas?

Men and women naturally store fat differently, so the calculation formulas account for these physiological differences.

How should I measure my waist and neck correctly?

Measure your neck just below the larynx, and your waist at the narrowest point, keeping the tape measure snug but not compressing the skin.