Body Fat Percentage Calculator
No scales with dubious sensors, no lab visit: three or four tape measurements and the US Navy circumference method give a body-fat estimate usually within a few points of far pricier methods.
Your numbers
Just below the Adam's apple.
At the navel, tape level, stomach relaxed.
Result
How it works
The US Navy developed this method because it needed something that worked with a tape measure on a ship. The formula relates the difference between waist and neck circumference (plus hips for women) to height, using logarithms — because fat distribution, not just total size, is what the tape is detecting. Against hydrostatic weighing it typically lands within 3–4 percentage points for most people.
Lean mass is everything that is not fat: muscle, bone, organs and water. Watching lean mass while dieting tells you whether the weight you are losing is the weight you meant to lose.
Good practice & limits
- Measure at the same time of day, before food, tape snug but not compressing the skin.
- Take each measurement twice and use the average — a centimetre of tape error moves the result noticeably.
- Track the waist alone between full measurements; it is the single most informative number of the set.