Body Fat Calculator
Estimate your body fat percentage with the US Navy tape method from a few measurements — free and 100% in your browser. Nothing is uploaded.
Report a problemThis is an estimate from the US Navy circumference method, not a body scan — it can be a few points off and is not medical advice. Talk to a health professional for guidance about your body composition.
How to use
- Pick your units (centimetres or inches) and your sex at the top.
- Measure your height, your neck just below the larynx, and your waist at the navel (women also measure the hip at its widest). Type each value.
- Read your estimated body fat percentage and category — they update live as you type, so there is nothing to submit.
FAQ
How does the US Navy body fat method work?
It estimates body fat from simple tape measurements instead of a body scan. For men it uses neck, waist and height; for women it adds the hip. Those circumferences go into a formula the US Navy developed, and the result is a body fat percentage. Measure on bare skin, keep the tape snug but not tight, and take each measurement twice for a steadier reading. It is quick and surprisingly close for most people, though it is still an estimate.
Is anything I type uploaded?
No. Your measurements are used for plain arithmetic right in your browser — nothing is uploaded or stored anywhere. The calculator works offline and keeps your numbers private.
How accurate is this number?
Treat it as a ballpark, not a diagnosis. The tape method is a rough estimate and can read a few percentage points high or low depending on your build and how carefully you measure. It is not medical advice. For a precise figure use a DEXA scan, and talk to a health professional about what your body composition means for you.