Smart scales use "bioelectrical impedance analysis (BIA) to estimate body composition by sending a low-level, painless electrical current through your body and measuring the resistance it encounters."

They are NOT a Dexa scan and do not offer T scores. They scan for bone "mass."

The scale I bought (there are many on the market) states that my bone mass is 3.7% and according to their chart mine should be 4%. I don't know how it compares to T scores. I just had my Dexa and it will be another two years so I am hoping it will help me track my bone trends (up, down or maintenance.) I was hoping someone here would have more experience.