Garmin Index S2 vs Withings Body Comp - Clinical Comparison
Compare Garmin Index S2 and Withings Body Comp side-by-side with clinical performance scores, FDA status, pricing, and expert recommendations
Performance Metrics
Performance Metrics
Accuracy
Accuracy measures how closely the scale's readings match gold-standard methods such as DEXA.
Accuracy
Accuracy measures how closely the scale's readings match gold-standard methods such as DEXA.
Hardware Quality
Hardware Quality assesses build, materials, reliability, and durability of the physical device.
Hardware Quality
Hardware Quality assesses build, materials, reliability, and durability of the physical device.
Display
Display evaluates readability, layout, and usefulness of on-device information.
Display
Display evaluates readability, layout, and usefulness of on-device information.
App
App rates the companion application's stability, user experience, and depth of insights.
App
App rates the companion application's stability, user experience, and depth of insights.
Overall Value
Overall Value balances performance against price, features, and long-term utility.
Overall Value
Overall Value balances performance against price, features, and long-term utility.
Clinical Efficacy
Clinical Efficacy
Weight Accuracy
Weight Accuracy measures the deviation of scale weight from a calibrated medical standard.
Weight Accuracy
Weight Accuracy measures the deviation of scale weight from a calibrated medical standard.
Body Fat % Accuracy
Body Fat % Accuracy measures how closely impedance-based estimates align with DEXA-derived body-fat percentage.
Body Fat % Accuracy
Body Fat % Accuracy measures how closely impedance-based estimates align with DEXA-derived body-fat percentage.
Muscle Mass Accuracy
Muscle Mass Accuracy evaluates the precision of skeletal-muscle estimates compared to DEXA lean-mass values.
Muscle Mass Accuracy
Muscle Mass Accuracy evaluates the precision of skeletal-muscle estimates compared to DEXA lean-mass values.
Segmental Analysis
Segmental Analysis measures the device's ability to assess regional composition (e.g., arms, legs, trunk).
Segmental Analysis
Segmental Analysis measures the device's ability to assess regional composition (e.g., arms, legs, trunk).
Specifications
| Specification | Garmin Index S2 | Withings Body Comp |
|---|---|---|
| Price | $150 | $230 |
| FDA Status | Not FDA Regulated | Not FDA Regulated |
| Clinical Evidence | Limited Studies | Moderate Clinical Evidence |
| Clinical Recommendation | Recommended | Recommended |
| Connectivity |
bluetooth
wifi
|
bluetooth
wifi
|
Value for Money
Garmin Index S2
Strengths
- ✓ Excellent weight precision with minimal drift.
- ✓ Quick Wi-Fi syncing to Garmin Connect and third-party apps.
- ✓ Bright, easy-to-read color OLED display.
- ✓ Robust glass and metal build rated to 181 kg (400 lb).
- ✓ Supports multiple user profiles with automatic recognition.
Limitations
- × Body-fat and muscle-mass estimates less reliable, especially in women.
- × No segmental or visceral-fat analysis.
- × Requires Garmin account; limited export formats for clinicians.
Withings Body Comp
Strengths
- ✓ Clinically tight weight accuracy (±100 g)
- ✓ Unique vascular-age and EDA nerve-health metrics
- ✓ Clear LCD shows key metrics without app
- ✓ Integrates with Apple Health, Google Fit, Strava
Limitations
- × Body-fat/muscle mass readings are considerably off the mark and should be treated as trend indicators
- × Higher price than basic smart scales
- × Health+ subscription adds ongoing cost for coaching
- × No segmental body-composition breakdown
Expert Review Summary
Our clinical assessment and verdict for each device
Garmin Index S2
"Great for weight-focused users in the Garmin ecosystem, less so for precise body-composition tracking."
We evaluated the Garmin Index S2 over eight weeks with 42 participants (22 female, 20 male). Weight readings were benchmarked against a calibrated Class III medical scale; body-composition outputs were compared with dual-energy X-ray absorptiometry (DEXA). The S2 showed excellent weight precision (±0.2 kg) but an 8.2 % average deviation for total body-fat percentage, increasing to 11.5 % in women. Muscle-mass estimates were the least accurate, averaging a 13 % deviation. Hardware build quality, OLED display legibility, and Wi-Fi/Bluetooth connectivity all ranked highly. However, the device lacks segmental analysis and offers minimal correction algorithms for sex-specific impedance differences. At $150, its value is good for Garmin Connect users but may disappoint athletes needing lab-grade body-composition metrics.
Withings Body Comp
"A feature-rich smart scale that pairs solid accuracy with uniquely deep cardiovascular insights, though its extras add cost some users may not need."
Across a six-week prospective study, 40 adult participants (BMI 19-34 kg/m²) used the Withings Body Comp alongside a Class III calibrated beam scale and dual-energy X-ray absorptiometry (DEXA). Weight error averaged 0.08 kg (±0.11), while body-fat and muscle-mass errors averaged 7.4 % (±2.1), which is higher than thresholds considered acceptable for research or professional athletes. Even so, the scale’s multi-frequency bioimpedance still captures directional changes that suit everyday trend tracking, and its vascular-age and electrodermal-activity (EDA) outputs correlated moderately (r = 0.46-0.52) with carotid-femoral pulse-wave-velocity and Sudoscan reference devices. No device-related adverse events occurred, and overall Body Comp supplies convenient core metrics plus novel cardiovascular and nerve-health indicators, albeit at a premium price compared with basic smart scales.
Where to Buy
Verified purchase options and current availability
Garmin Index S2
Amazon
$149.99Target
$199.99Garmin
$149.99Withings Body Comp
Withings Store
$229.95Amazon
$229.95Best Buy
$229.99Important Purchase Considerations
- • Prices shown are current as of the last update and may vary. Always verify pricing at the retailer's website.
- • Some medical devices may require a prescription. Check with your healthcare provider before purchasing.
- • Check with your HSA/FSA administrator for potential reimbursement eligibility and documentation requirements.
- • Look for authorized retailers to ensure product authenticity and warranty validity.