Garmin sued over Index S2 smart scale accuracy claims

Garmin is facing a proposed class action lawsuit over the Index S2 Smart Scale, with the complaint taking aim at its body composition readings. The case was filed in Illinois by a consumer who argues Garmin marketed the scale’s body fat, muscle mass and related metrics as accurate, even though the lawsuit says the technology cannot deliver that level of precision.

The lawsuit is listed as Maurer v. Garmin International, Inc. et al, case number 1:26-cv-06389, in the U.S. District Court for the Northern District of Illinois. It was filed on May 29, 2026 by Victor Maurer, with Garmin International named among the defendants. The docket lists it as an “Other Fraud” case, with a jury demand and a 56-page complaint.

At this stage, this is still an allegation. Garmin has not yet had its say in court, and a proposed class action is not the same as a finding that the company did anything wrong.

What the lawsuit claims

The complaint focuses on the Garmin Index S2 Smart Scale, so the latest version of its smart scale. The issue is the body composition side.

According to the complaint, Garmin “failed to disclose” key information about the scale’s alleged inability to accurately measure body composition. The plaintiff is seeking monetary damages and a declaration that the Garmin smart scale cannot accurately measure body composition.

The wording used in the lawsuit is pretty direct. It claims that the foot-to-foot bioelectrical impedance technology in the scale is “incapable of accurate body composition measurements,” making Garmin’s representations allegedly false, misleading and deceptive to consumers.

That is the heart of the case. The plaintiff is not simply saying smart scale readings vary from day to day. He is arguing that the technology Garmin uses does not support the accuracy message attached to the product.

The problem with foot-to-foot BIA

The Index S2 uses bioelectrical impedance analysis, often shortened to BIA. This works by sending a small electrical signal through the body and measuring resistance. From there, the scale estimates body water, fat mass, muscle mass and other values.

The lawsuit argues that foot-to-foot BIA has a basic limitation. Because the user stands barefoot on the scale, the signal travels through the lower body rather than the whole body. That can make the estimate less representative of total body composition, especially when compared with more advanced methods.

The complaint reportedly cites a 2021 JMIR mHealth and uHealth study that compared three foot-to-foot smart scales with DEXA. According to the filing, those smart scales underestimated both fat mass and muscle mass by as much as around 8kg, or up to 8 percentage points!

Garmin’s accuracy language is the key issue

The legal question will probably come down to marketing language. Smart scales can be useful for trends, especially if someone weighs themselves under similar conditions each time. But there is a big difference between trend tracking and presenting body composition numbers as accurate measurements.

The lawsuit points to Garmin and retailer descriptions. Garmin’s own product page uses the phrase “Accuracy matters when it comes to your goals.” The complaint also references an Amazon listing that tells buyers they can get accurate measurements for weight, weight trend, body fat percentage, BMI, skeletal muscle mass and more.

Garmin may argue that consumer smart scales provide estimates and that users understand these are not clinical-grade measurements. The plaintiff will likely argue that ordinary buyers saw the accuracy language and reasonably expected more precise body composition data than the scale could provide.

Why one person can take this to court

The named plaintiff is Victor Maurer, a private individual consumer. That does not mean he is personally funding a solo legal battle against Garmin. This is a proposed class action, which means the case aims to represent a larger group of buyers who allegedly purchased the product under the same kind of marketing claims.

One person’s potential loss might only be the cost of the scale. But if a court certifies a class, the claim can potentially cover many buyers. That is why consumer class actions often start with one named plaintiff but are driven by law firms looking at the broader market.

The case still faces several hurdles. Garmin could seek dismissal. The plaintiff would also need to clear the class certification stage if the case gets that far. Many consumer class actions settle, narrow or disappear before trial, so this should not be treated as a guaranteed win for the plaintiff.

Still, the filing taps into something many smart scale users already suspect. Weight readings are one thing. Body fat percentage, muscle mass and body water are another. Those numbers look precise on a screen, but the technology behind them often works more like an estimate engine than a measurement tool.

Source: Case details checked against PacerMonitor, Law360 and Singletracks. The complaint was filed on May 29, 2026 in the Northern District of Illinois as Maurer v. Garmin International, Inc. et al, case number 1:26-cv-06389.