General estimate
Body Fat Estimate
Uses circumference inputs for a rough population-level estimate.
How this estimate is calculated
The US Navy circumference method, which estimates body fat from the ratio between waist, neck, hip and height.
How to use the result
Treat it as a starting point to compare against how you actually feel and what you actually eat. Estimates are most useful for spotting a large gap, not for chasing a precise number.
What this cannot tell you
Circumference methods carry an error of roughly ±3–4 percentage points against DXA scanning, and they assume a typical fat distribution. Measure in the same place each time if you want to track change.
Estimates, not measurements: this tool runs a population equation, so it describes a typical person with your inputs rather than measuring you. Where a number drives a decision about a diagnosed condition or medication, have a dietitian or clinician sanity-check it against your history.