Navy method estimate
Body Fat Calculator
Estimate your body fat percentage from simple tape measurements, then use your result to calculate lean body mass and FFMI.
Default is Imperial. Metric is available if you prefer centimeters and kilograms.
Body Fat Calculator
Estimate body fat percentage
Estimate Body Fat →Lean Body Mass Calculator
Calculate lean mass and fat mass
Calculate Lean Mass →FFMI Calculator
Calculate FFMI and normalized FFMI
Calculate FFMI →Body Fat Percentage Calculator
Your Body Fat Estimate
U.S. Navy circumference method · Free · No sign-up
Guide
How the US Navy Body Fat Formula Works
The US Navy body fat formula estimates body fat percentage from tape measurements. For men, it uses height, neck, and waist. For women, it also uses hips.
The method is useful because it is fast, free, and more practical than visual guessing. You can repeat the same measurements over time and use the result in the FFMI Calculator or Lean Body Mass Calculator.
It is still an estimate, not a medical scan. Hydration, posture, measuring location, and tape tension can change the result, so use the same measuring method each time.
How to Measure for a Better Estimate
The Navy method is only as consistent as your measurements. Use a soft tape, measure in the same conditions each time, and avoid pulling the tape so tight that it compresses the skin.
Waist
Measure around the abdomen at about navel level while standing relaxed. Do not suck in your stomach.
Neck
Measure below the Adam's apple, keeping the tape level and snug without pressing into the skin.
Hips
For women, measure around the widest part of the hips and glutes with feet together.
Timing
Measure at the same time of day, ideally before training and before a large meal, to reduce day-to-day noise.
Related Body Composition Guides
Use these next steps to compare body composition metrics and turn your body fat estimate into a better FFMI result.
Frequently Asked Questions
Where should I measure my waist?
For consistency, measure around the abdomen at about navel level. Keep the tape snug but not compressed.
Is the Navy body fat formula accurate?
It is useful for quick estimates and trend tracking, but it is not as precise as a medical scan. Measurement consistency matters a lot.
Why does neck size matter?
The formula compares neck size with waist size because those measurements help estimate body fat distribution from circumference data.
Is the Navy method better than smart scales?
It depends. Smart scales can swing with hydration and device quality, while the Navy method is simple and repeatable if you measure carefully.
Why do women need a hip measurement?
The Navy formula uses different equations for men and women. The female equation includes hip circumference.
Is this better than a DEXA scan?
No. DEXA and other lab methods can be more precise. This calculator is best used as a free estimate and tracking tool.
Can I use this result for FFMI?
Yes. FFMI needs body fat percentage to estimate lean mass. After estimating body fat here, use that number in the FFMI calculator.