Body Fat Calculator
Calculate body fat percentage using the US Navy method.
Body Fat Percentage
How is Body Fat Calculated?
The US Navy Method estimates body fat using waist, neck, and height measurements (plus hips for women). It is widely accepted for tracking body composition changes over time.
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Estimating Your Body Fat Percentage
Overview
Body fat percentage describes how much of your body weight is fat versus lean mass — a better health indicator than weight alone. This calculator estimates it from body measurements using the U.S. Navy method, instantly in your browser. It is an estimate, not a clinical measurement.
How to Use (Step by Step)
- 1
Enter your measurements
Height, neck, and waist (plus hips for women), measured with a tape.
- 2
Select your sex
The formula differs for men and women.
- 3
Read your estimate
Use it as a baseline and re-measure periodically to track the trend.
How It Works
The U.S. Navy formula estimates body fat from circumference measurements — neck and waist (and hips for women) relative to height — without special equipment. It correlates reasonably with more precise methods for most people. Because it relies on tape measurements, accuracy depends on measuring consistently at the right spots; tracking the trend over time is more reliable than any single reading.
When to Use This
Tracking fat loss when the scale alone is misleading. Setting a body-composition goal alongside weight. Getting a no-equipment estimate to monitor progress over time.
Frequently Asked Questions
It is a reasonable estimate for most people, typically within a few percentage points of more precise methods, as long as you measure carefully and consistently.
Important Notes
Body-fat estimates from measurements are approximate and for informational purposes only — they are not a medical diagnosis. Consult a qualified healthcare professional before making health or fitness decisions.