Garmin Faces Class-Action Lawsuit Over Index S2 Smart Scale Accuracy Claims
Garmin is facing a class-action lawsuit in the United States over claims that its Index S2 smart scale may have been marketed in a misleading way. The complaint focuses on whether the device can accurately measure body composition metrics such as body fat percentage, muscle mass, bone mass and other health-related data.
At the center of the case is the Garmin Index S2, a connected smart scale that uses bioelectrical impedance analysis, often called BIA. This method sends a small electrical current through the body and estimates body composition based on how that current moves through different tissues. The technology is common in consumer smart scales, but it also comes with well-known limitations.
The lawsuit, filed in the U.S. District Court for the Northern District of Illinois, argues that Garmin’s marketing gave customers the impression that the Index S2 could provide accurate body composition measurements. According to the complaint, plaintiff Victor Maurer purchased the scale in August 2024 and later noticed major differences between the scale’s readings and the results from a DEXA scan, a more advanced body composition analysis method often used in clinical or professional settings.
The key issue is not simply whether the Garmin Index S2 can produce useful estimates, but whether the company’s accuracy claims go too far. Consumer smart scales with foot-only electrodes measure electrical resistance through the lower body, typically from one leg to the other. Because the current does not travel through the entire body in the same way a full-body measurement system might, the results may be more reflective of lower-body composition than total-body fat percentage.
That does not mean smart scales are useless. For many users, devices like the Garmin Index S2 can still be helpful for tracking long-term trends, especially when measurements are taken consistently under similar conditions. If a user weighs in at the same time of day and under similar hydration levels, the scale may show whether body composition estimates are moving up or down over time.
However, body fat measurement is complicated. Hydration, recent exercise, food intake, skin temperature and individual fat distribution can all affect bioelectrical impedance readings. Even professional methods have margins of error. DEXA scans require specialized equipment, while skinfold caliper measurements can vary depending on the skill of the person performing the test. In other words, obtaining a truly precise body fat reading is far more difficult than many consumer health gadgets suggest.
The complaint reportedly cites studies related to the limitations of two-foot bioelectrical impedance devices and argues that Garmin should not present the Index S2’s measurements as highly accurate if the technology cannot reliably deliver that level of precision for every user.
The lawsuit seeks to stop the allegedly misleading marketing and also asks for financial compensation, including legal costs. If the case moves forward, it could put more pressure on fitness and wearable tech companies to be clearer about what their devices can and cannot measure.
The broader takeaway for consumers is simple: smart scales can be useful tools, but they should not be treated as medical-grade body composition analyzers. The Garmin Index S2 and similar devices may help users monitor weight and general trends over time, but their body fat percentage readings should be viewed as estimates rather than exact measurements.
For anyone serious about tracking body composition, the best approach is to combine multiple indicators: weight trends, waist measurements, progress photos, fitness performance and, when available, professional testing. Smart scales can play a role in that picture, but the current lawsuit highlights why accuracy claims in health technology need to be carefully examined.
