Wyze Scale uses Bio-electric Impedance Analysis (BIA)
With BIA, a weak (and safe) electric current flows through the body, passing through muscle and fat. Because most of our body water is stored in our muscles, this current moves faster through muscle and slows down through fat. BIA measures that resistance, resulting in Body Fat Percentage.
Personal Info + Real-time Data = Body Composition
Wyze Scale combines the personal information you entered during set up (gender, age, height) with real-time data (weight, impedance) to calculate your other body composition measurements.
It's important that you enter your personal info correctly. If your height is off by a few inches, or your age is off by a few years, measurements like BMI, body water, and metabolic age may be inaccurate.
Check out What can my Wyze Scale measure? for more details.