How the Navy body-fat formula actually works
The math behind circumference-based body composition estimates, decoded.
Body Composition — U.S. Navy Method
What's your true body fat?
BMI hides where your weight sits. FatPulse uses the U.S. Navy circumference method to estimate your body fat from a tape measure alone — no scale, no clinic visit.
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% body fat
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Body fat estimate
Measuring…
—Lean mass
—Fat mass
—BMI
Where you sit · ACE ranges
Navy vs. BMI estimate
U.S. Navy
BMI formula—
Target your body fat
%
—Target weight
—Fat to lose
—Est. time
Estimates only — not medical advice. Individual variation is normal.
Why it works
The Navy method reads your waist, not your wallet
Research-grade body fat tests (DEXA, hydrostatic) cost time and money. The U.S. Navy circumference method uses age, sex and tape-measure figures to match clinical estimates within a few points — accurate enough to track monthly progress.
- Measure neck, waist and (for women) hip at their widest point.
- Convert inches to the formula — FatPulse does this automatically.
- Compare against ACE ranges so you know whether you're in "fitness" or "acceptable".
- Target a realistic body fat and work back from a safe weekly fat-loss rate.
a quick check between milestones
FatPulse gives you a body fat percentage estimate in seconds using the U.S. Navy circumference method. It's built for people who track progress between DEXA scans or hydrostatic tests, or who don't have access to clinical measurement at all. If you're cutting, bulking, or just want a consistent reference point week to week, this tool turns five tape-measure numbers into a single figure you can log. It's not a diagnostic instrument, but it's reliable enough to spot trends over time.
Body fat basics
Is body fat percentage better than BMI?
Generally yes for tracking body composition. BMI only compares weight to height and can't tell muscle from fat, so a lean athlete score can look "overweight". Body fat percentage measures what's actually fat versus lean tissue.
How accurate is the U.S. Navy method?
Within about 3 percentage points of DEXA for most people when measurements are taken correctly. Consistency matters more than precision — measure the same spot at the same time of day to see true trends.
How fast can I safely lower body fat?
A target of roughly 0.5–1% of body weight per week (a 250–500 kcal daily deficit) preserves muscle and is widely considered sustainable. Plan on losing about 0.5–1% body fat per month as a realistic benchmark.
What's a healthy body fat for a man vs. a woman?
Essential levels are about 2–5% for men and 10–13% for women. Athletic ranges run 6–13% (men) and 14–20% (women); acceptable zones are roughly 18–24% (men) and 25–31% (women).