Body Fat Calculator โ€” US Navy Tape Method

The scale can't tell fat from muscle. Enter height, neck and waist (hips if female) to estimate your body fat percentage, fat mass and lean mass using the US Navy formula.

Quick answer: Free body fat calculator using the US Navy tape method: measure neck, waist (and hips for women) to estimate body fat percentage, fat mass and lean mass instantly.

โ€“Body fat %
โ€“ACE category
โ€“Fat mass
โ€“Lean mass
leanobese

๐Ÿ’ก Estimates from circumference formulas โ€” track the trend over time, not single-day perfection.

How to use

  1. Measure with a tape โ€” neck below the larynx; waist at the navel (men) or narrowest point (women); hips at the widest point (women only).
  2. Enter your numbers โ€” pick metric or imperial, male or female.
  3. Read your estimate โ€” body fat %, fat/lean mass split and where you sit in the ACE reference ranges.

About this tool

Body fat percentage is a far better health signal than weight alone. This calculator implements the US Navy circumference method (the standard field test): log10-based equations using height, neck and waist for men, plus hip for women. You get estimated body fat %, your fat mass vs lean mass in kg/lb, the American Council on Exercise reference ranges (essential โ†’ athletic โ†’ average โ†’ obese) and a simple visual gauge. Tape measurements are estimates โ€” consistency in measuring matters more than perfection.

FAQ

How accurate is the Navy method?
Within ~3-4% of DEXA scans for most people when measurements are careful โ€” good enough to track trends, which matters more than the absolute number.
What is a healthy body fat percentage?
For men ~10-20% is typical-healthy, for women ~18-28%. Athletes run lower; essential fat is ~3% (men) and ~12% (women).
Why do women need a hip measurement?
Female fat distribution concentrates around hips/thighs; including hip circumference makes the Navy formula significantly more accurate for women.