Smart scales are connected weighing devices that use bioelectrical impedance analysis (BIA) to estimate body composition — body fat percentage, muscle mass, bone mass, and hydration — alongside weight. They sync to smartphone apps via Bluetooth or WiFi, maintaining a historical record of your measurements over time.
The accuracy of the body composition estimates depends on the scale's calibration, the measurement frequency (single vs dual vs multi-frequency BIA), and — critically — how consistently you measure. Published research places the best consumer BIA scales at approximately ±3–5 percentage points for body fat versus DEXA scan. For trend tracking over weeks and months, this precision is sufficient. For precise body composition benchmarking, a clinical DEXA scan is the right tool.
GreatHealthGear evaluates smart scales by aggregating peer-reviewed BIA validation research, manufacturer specifications, and long-term user data from verified purchasers. No device is tested in-house. Every score reflects the weight of external evidence — that makes our conclusions slower to form and harder to distort.