Body Fat Calculator
Estimate your body fat percentage with the U.S. Navy method. Enter a few tape measurements to see your result and category.
Enter Your Measurements
All you need is a flexible tape measure.
Your Results
Enter your measurements and click calculate. Your estimated body fat percentage and category will appear here.
About the Navy Method
The U.S. Navy method estimates body fat percentage from circumference measurements instead of skinfold calipers or lab equipment. It is not as precise as a DEXA scan, but it is free, repeatable, and good for tracking trends over time.
Body measurements shift with hydration and food intake, so measuring first thing in the morning keeps results consistent.
Pulling the tape too tight will underestimate your measurements and skew the result lower than reality.
A single measurement has some error. Re-measure every few weeks and watch the direction it moves.
Body Fat Calculator Questions
How Accurate Is the Navy Method Body Fat Calculator?
The Navy method is generally accurate within about 3-4% of body fat compared to lab methods like DEXA scans, for most people. It is less reliable for very lean or very heavy individuals, and for people with unusual body proportions.
Where Do I Measure My Neck and Waist?
Measure your neck just below the larynx, with the tape sloping slightly downward at the front. Measure your waist at the narrowest point, usually near the navel, without pulling the tape tight.
How Often Should I Re-Measure Body Fat?
Every 2-4 weeks is usually enough to see a meaningful trend. Measuring more often mostly captures day-to-day water and food weight changes, not real body composition change.
Turn This Into a Nutrition Plan
Use your body fat result alongside the calorie and macro calculators to set targets that match your goal.