Body Fat Calculator – Estimate Your Body Fat Percentage
Please enter valid measurements for all required fields.
What Is Body Fat Percentage?
Body fat percentage is the proportion of your total body weight that consists of fat, as opposed to muscle, bone, water, and organs. Unlike BMI, which only considers height and weight, body fat percentage gives a more direct picture of body composition.
Formula Used (U.S. Navy Method)
Men: Body Fat % = 86.010 × log10(waist − neck) − 70.041 × log10(height) + 36.76
Women: Body Fat % = 163.205 × log10(waist + hip − neck) − 97.684 × log10(height) − 78.387
This method, developed by the U.S. Navy, uses simple circumference measurements and is widely used because it doesn't require any special equipment — just a measuring tape.
How to Use This Calculator
Select your unit system and gender, then measure your neck, waist (and hip, if female) with a flexible tape measure. Enter your height and measurements, then click "Calculate Body Fat" for your instant result.
Body Fat Percentage Categories
| Category | Men | Women |
|---|---|---|
| Essential Fat | 2–5% | 10–13% |
| Athletes | 6–13% | 14–20% |
| Fitness | 14–17% | 21–24% |
| Acceptable | 18–24% | 25–31% |
| Obese | 25%+ | 32%+ |
Frequently Asked Questions
How accurate is the Navy body fat method?
It's reasonably accurate for most people, typically within 3-4% of more advanced methods like DEXA scans, making it a solid free alternative.
Where do I measure my waist and neck?
Measure your neck just below the larynx, and your waist at the narrowest point (or at the navel level if no natural narrowing is visible).
Why does the formula need my hip measurement only for women?
Fat distribution patterns differ by sex, so the Navy formula for women includes hip circumference to improve accuracy.
Is body fat percentage more useful than BMI?
Yes, for assessing actual body composition — BMI can't tell the difference between muscle and fat, while body fat percentage measures it directly.