Garmin Index S2 Review: Is It Worth It in 2025? 10-Month Real-World Test
- Helge Mathisen
- 15. sep.
- 5 min lesing
After 10 months of daily use during endurance training, here's my honest take on whether the Garmin Index Scale S2 justifies its premium price tag. Get the Garmin Index Scale S2 Here
Like many fitness enthusiasts, I decided to take a more data-driven approach to my training—specifically for an endurance race this past summer. The Garmin Index S2 seemed like the perfect tool to complement my existing Garmin ecosystem. But after 10 months of daily use, is this smart scale worth the investment in 2025?
The Garmin Index S2: Quick Overview
The Index S2 launched back in October 2020, making it almost 5 years old now. Despite its age, it still retails for $149.99—a premium price in the smart scale market. Here are the key specifications:
Power: Four AAA batteries (up to 9+ months battery life)
Capacity: Supports up to 16 different users
Connectivity: Wi-Fi, Bluetooth, and ANT+
Display: Color LCD with customizable metrics
Colors: Available in black and white
How the Technology Works
The Index S2 uses bioelectrical impedance analysis (BIA)—specifically, a foot-to-foot method. When you step on the scale with bare feet, it sends a tiny, unnoticeable electrical current from one foot through your body to the other. The scale measures the electrical resistance to estimate your body composition.
What It Actually Measures
The scale provides a comprehensive suite of metrics:
Weight (pounds, kilograms, or stones)
30-day weight trend graph (displayed directly on the scale)
Body Mass Index (BMI)
Body fat percentage
Skeletal muscle mass
Bone mass
Body water percentage
Local weather forecast (a quirky but appreciated addition)
Setup and User Experience
Setting up the Index S2 is refreshingly straightforward through the Garmin Connect app. The scale can store up to 7 different Wi-Fi networks, making it versatile for travel or multi-location use. It also includes carpet feet if you need to use it on soft surfaces.
Multi-User Recognition
One standout feature is automatic user recognition. The scale identifies who's stepping on based on weight patterns and historical data. During my 10-month test period, it never confused me with my partner (who weighs significantly less). However, some users report issues with similar-weight family members.
What I Love About the Index S2
Pure Convenience
The biggest selling point is undoubtedly convenience. I step on the scale each morning, and within seconds, my data automatically syncs to Garmin Connect via Wi-Fi. No phone needed, no manual logging—it just works seamlessly.
Accurate Weight Measurements
Let's be clear: the actual weight measurements are spot-on accurate. Throughout my testing, I've compared readings with commercial gym scales multiple times, and the Index S2 consistently measures within 0.2 pounds. For weight trend tracking, this scale delivers reliable, consistent data.
The Reality Check: Body Composition Accuracy
Here's where things get complicated. While the weight measurements excel, the body composition metrics require a more nuanced discussion.
The Science Behind BIA Limitations
As of 2025, there are no peer-reviewed validation studies testing the Garmin Index S2 specifically against gold standards like DXA scans. Looking at research on consumer BIA scales in general, the scientific consensus is concerning: foot-to-foot BIA is not recommended for individual clinical assessment due to unacceptably high error rates.
Research consistently shows these scales:
Underestimate body fat percentage with biases ranging from 1.3% to 12.8%
Perform worse for individuals with higher body fat
Are extremely sensitive to hydration levels (dehydration can cause 5kg errors in fat-free mass estimates)
Real-World Experience
My personal experience aligns with the research. The scale tends to underestimate my body fat percentage significantly. Since most of my body fat is stored from the hips up, and the current only passes through my legs, the readings don't reflect my actual composition accurately.
User Reports and Community Feedback
Consistent reports across Reddit and Garmin's forums echo the same sentiment: excellent weight tracking, questionable body composition accuracy—especially for fit, lean, or older athletes.
Maximizing Accuracy: Best Practices
If you decide to use the Index S2, here's how to get the most consistent data:
Be Disciplined About Timing
Weigh yourself at the same time daily (ideally morning, post-bathroom, pre-food/drink)
Avoid hard training, saunas, or alcohol 12-24 hours before weighing
Ensure feet are dry, warm, and positioned consistently
Use the Right Settings
Enable "Athlete Mode" in Garmin Connect (Activity Class setting of 8 or higher)
Experiment with this setting to see if it improves accuracy for your body type
Establish a Baseline
The most effective approach is getting one professional DXA scan for comparison. If the DXA shows 15% body fat and your scale reads 19%, you now have a 4-point offset to track changes from that baseline.
Focus on Trends, Not Daily Numbers
Ignore daily fluctuations entirely. Focus on weekly or monthly averages to identify real patterns in your body composition changes.
Price Analysis: What You're Actually Buying
At $149.99 MSRP (frequently on sale for $89-119), you're paying a premium for:
Wi-Fi connectivity and automatic syncing
Multi-user recognition
Seamless Garmin ecosystem integration
Color display with trend visualization
Weather integration
Alternatives to Consider
Budget Option (15-50)
Basic digital scale ($15-30) paired with body fat calipers ($15) provides more accurate body composition estimates at a fraction of the cost.
Mid-Range Smart Scale ($99.95)
The Withings Body Smart offers accurate weight measurements, body composition metrics, heart rate monitoring, and a color display—making it the current entry point for quality smart scales.
Garmin Connect Workarounds
The MyFitnessPal Bridge - Still requres a wifi connected scale
You can sync other scales to Garmin Connect using MyFitnessPal as a middleman. Compatible budget options include:
Limitation: Only weight data transfers, and the connection can be unreliable.
This paid service syncs ALL body composition data from supported scales (like Withings) into Garmin Connect, offering better functionality than the free bridge method.
Who Should Buy the Index S2?
Perfect For:
Garmin ecosystem users who want seamless data integration
Data enthusiasts who value automated tracking
Athletes focused on long-term weight trend analysis
Families or teams needing multi-user support
Consider Alternatives If:
You're budget-conscious
You only weigh yourself occasionally
You need clinically accurate body composition data
You don't use other Garmin products
The Verdict: Is It Worth It in 2025?
After 10 months of daily use, the Garmin Index S2 is fundamentally a convenience purchase, not an accuracy purchase (except for weight measurements).
Final Score: 3.5/5 Stars
The Good:
Exceptional weight accuracy and reliability
Seamless Garmin ecosystem integration
Excellent build quality and user experience
Impressive battery life (approaching 1+ years)
Effective multi-user recognition
The Not-So-Good:
Body composition metrics have significant accuracy limitations
Premium pricing for 5-year-old technology
Limited value outside the Garmin ecosystem
Bottom Line:
The Index S2 is worth considering if you're deeply invested in the Garmin ecosystem and can find it on sale ($89-119). For pure weight tracking with excellent convenience, it delivers. However, if you need accurate body composition data or are budget-conscious, there are better alternatives available.
If you currently own the original Index scale, the upgrade probably isn't worth it unless you specifically want the color display and improved user recognition.
The Index S2 excels at what it does best—making weight tracking effortless for Garmin users—but don't expect miracles from its body composition analysis. Get the Garmin Index Scale S2 Here
Get a Body Fat Callipper here
or get a simple digital body weight here
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