The Garmin Index S2, often called the Garmin Index 2, is one of the most convenient scales for people already using Garmin products. It recognises the user, uploads results over Wi‑Fi and builds clear trends in Garmin Connect. After many months of use, however, I have one major reservation: it tracks weight conveniently, but I treat its body-composition figures as estimates rather than medical measurements.
I bought the scale after an injury and some weight gain. I wanted weight, body fat and muscle data alongside the training information from my Garmin watch and in Apple Health. This review separates Garmin’s specifications from my experience and includes a later comparison with an InBody120 analyser.
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Garmin Index 2: the short verdict
- Biggest strength: effortless Wi‑Fi syncing and excellent integration with Garmin Connect.
- Biggest weakness: body composition is estimated with BIA, and my comparison differed substantially from an InBody120 result.
- Best for: Garmin watch users who want weight and trends in the same app.
- Not for: anyone expecting a detailed analysis or clinical-level accuracy.
Garmin Index S2 specifications
Garmin lists dimensions of 320 × 310 × 28 mm, a weight of about 2 kg, a 181.4 kg capacity, a colour display, 2.4 GHz Wi‑Fi, Bluetooth and ANT connectivity, and up to nine months of battery life from four AAA batteries. Carpet feet are included, and the scale supports up to 16 user profiles. Source: Garmin Index S2 product page.
- Measurements: weight, BMI, body-fat percentage, skeletal muscle mass, bone mass and body-water percentage,
- Trends: change since the previous weigh-in and a 30-day weight graph,
- Sync: automatic uploads to Garmin Connect over Wi‑Fi,
- Users: up to 16 individual profiles,
- Extras: configurable widgets and a weather forecast.
People with pacemakers or other implanted electronic devices should not use the impedance measurement. Garmin also advises consulting a physician during pregnancy or suspected pregnancy.
Setup and everyday use
Setup is straightforward: add the device in Garmin Connect, connect it to your home Wi‑Fi and choose the widgets you want to see. After that, your phone does not need to be beside the scale. Step on barefoot, wait for your initials and step off once it recognises your profile.
Convenience is what separated the Index S2 from my previous scale. I had to open an app before using the old one; Garmin uploads on its own. When sharing is enabled, Garmin Connect can also send weight, BMI, body-fat percentage and water data to Apple Health. The flow is from Garmin to Apple Health, not the other way around. Source: Garmin Support.
Multiple profiles are less polished. Each person needs a Garmin Connect account and an invitation to use the scale. I added three users without trouble, but an interrupted fourth setup caused a measurement to reach the wrong account. I fixed it, but the process is not particularly forgiving.
What does the Garmin Index S2 actually measure?
Weight comes from the scale’s load sensors. The other body-composition values are calculated through bioelectrical impedance: a small current travels from one foot to the other, and the device uses electrical resistance to estimate fat, water, muscle and bone mass. Garmin explains the method and its limitations in the manual.
Hydration and measurement conditions affect the result. Eating, drinking, training, bathing or using a sauna can temporarily change the figures. Consistency matters, so weigh yourself at a similar time and under similar conditions; Garmin recommends waiting two hours after those activities.
The data set is adequate for day-to-day tracking but not especially broad. There is no separate visceral- and subcutaneous-fat breakdown or more advanced segmental analysis. My cheaper previous scale showed more indicators, although a longer list does not automatically mean better accuracy.
Garmin Index 2 vs InBody120
In a later comparison, Garmin Connect reported 30.8 kg of skeletal muscle and 22.4% body fat. The InBody120 reported 35.1 kg and 16.5%, respectively. That is a 4.3 kg difference in muscle and a 5.9-percentage-point difference in body fat. The gap is large enough that I would not use Garmin’s body-composition values for medical decisions.
This was one comparison, not a validation study. It does not prove that the InBody result was perfect or that every Index S2 will differ in the same way. The InBody120 does, however, measure five body segments at two frequencies through eight contact points, while Garmin measures through the feet. Source: InBody120 user manual. The fairest use of Garmin’s estimate is to watch the trend under repeatable conditions.
Is it useful for athletes?
Yes, mainly as a frictionless record of weight and change over time. For a runner or cyclist, current weight can help put training load and relative performance metrics into context, and Garmin Connect stores it beside workouts, sleep and other wellness data. That integration matters more to me than the weather widget or any single BIA estimate.
I trust the process most when it is consistent: the same scale, a similar time of day, a hard and level floor, and similar hydration. Under those conditions the graph can show direction even when the absolute fat or muscle value is imperfect.
Pros and cons
Pros
- automatic Wi‑Fi syncing,
- clear trends in Garmin Connect,
- automatic recognition for up to 16 users,
- colour display and selectable widgets,
- excellent integration with Garmin products and optional Apple Health sharing.
Cons
- large body-composition differences in my InBody120 comparison,
- fewer detailed metrics than some cheaper apps,
- awkward recovery when multi-user setup goes wrong,
- hard to justify the price outside the Garmin ecosystem,
- BIA results are sensitive to measurement conditions.
Who should buy the Garmin Index S2?
It makes the most sense for someone who already owns a Garmin watch or bike computer and wants weight to enter the same ecosystem without manual work. It can also suit a household, provided that everyone has an account and the profiles are configured correctly.
If low cost, a very wide set of indicators or body-composition analysis closer to professional equipment matters most, compare alternatives. More metrics alone are not enough; repeatability and measurement method matter too.
Verdict after many months
The Garmin Index S2 won me over through convenience. I step on, it recognises my profile, cycles through the screens and uploads the data without a phone beside it. That simple workflow keeps me weighing consistently and gives me a useful trend.
I would not buy it for body-composition analysis alone. I treat fat and muscle estimates cautiously, especially after the InBody120 discrepancy. For a Garmin user it is a good automatic weight tracker; for everyone else, the price is much harder to defend.
Frequently asked questions
Is the Garmin Index S2 accurate?
Its weight reading is useful for consistent tracking. Body composition is estimated through BIA and varies with hydration and measurement conditions, so it does not replace a medical assessment.
Is the Garmin Index 2 worth buying?
Yes, if you use Garmin Connect and value automatic syncing. Without the Garmin ecosystem, the measurement set alone does not make the price especially compelling.
How can I make measurements more repeatable?
Weigh yourself barefoot at a similar time, on a hard and level floor, and with similar hydration. Garmin recommends waiting two hours after eating, drinking, training, bathing or using a sauna.
Does Garmin Index S2 work with Apple Health?
Garmin Connect can send weight, BMI, body-fat percentage and body-water data to Apple Health when the relevant permissions are enabled. It does not pull data back from Apple Health.
How many users does it support?
Up to 16. Each person needs a Garmin Connect account and an invitation to use the scale.
Does the InBody result prove Garmin is wrong?
No. It was a single comparison between two BIA devices rather than a laboratory study. It does show that absolute body-composition values can differ substantially and should be interpreted with care.