Body Fat (Navy Method)
Tape-measure body fat estimate used by the US Navy.
Grab a soft tape measure — enter your height, neck and waist (plus hips for women) to estimate your body fat percentage with the US Navy tape method, see your ACE category, and track your trend privately on this device.
How this is calculated
Methodology & sources
- Formula: Hodgdon JA & Beckett MB (1984), Prediction of Percent Body Fat for U.S. Navy Men and Women from Body Circumferences and Height, Naval Health Research Center — equations reproduced in Potter et al. 2022, Circumference-Based Predictions of Body Fat Revisited (PMC9008774)
- Categories: American Council on Exercise (ACE) body-fat percentage chart — general adult ranges, not age-adjusted and not targets
Privacy — how your data is handled
All math runs in your browser on your device. Nothing you type is sent to a server,
and saved results live only in this browser's local storage. Tools that use live
public data (food databases, weather) request only what they need to display.
📏 Practical toolkit tip — Self-Tightening Body Tape Measure (MyoTape style, ~$7)
Why it helps: Locks around your waist, hips, or neck with consistent spring tension so you don’t accidentally pull tighter from week to week.
Pro tip: Always measure on bare skin after a normal, relaxed exhale first thing in the morning.