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In this guide
The Garmin Index S2 measures your weight and estimates the rest, and its owner's manual says so plainly: a small current crosses from one foot to the other, and the signal is used to "estimate aspects of your body composition." Amazon, selling it directly, and Garmin.com both listed it at $199.99 on 2026-09-27.
The useful comparison is the $129.95 Withings Body Smart, which also syncs over Wi-Fi, also estimates composition and also has a color screen. What Garmin charges $70 more for is sixteen user slots instead of eight, a 30-day weight trend and a weather widget on its display, and a home in Garmin Connect.
Our verdict
Buy the $199.99 Index S2 when your data already lives in Garmin Connect or more than eight people will weigh in; otherwise the $129.95 Withings Body Smart also syncs over Wi-Fi, has a color screen and estimates composition from foot-to-foot impedance too.
- A good fit for
- Garmin households and families of nine to sixteen weighers who want a 30-day trend on the scale, weighed barefoot at the same hour each morning.
- We would skip it if
- Skip it if anyone who will use it has a pacemaker or other internal electronic device, if you want pregnancy or baby modes, or to save $70 with the Withings Body Smart.
Reasons to consider it
- Wi-Fi uploads with no phone present, sixteen user profiles recognized by initials at step-off, and a color display carrying the 30-day weight trend plus a weather widget
- The manual spells out the estimation method and the repeatability protocol in plain words, and each user can switch off the composition figures they do not want recorded
- Up to nine months on four AAA batteries, a 400 lb maximum load, and one price, $199.99, on Garmin.com and Amazon, with HSA/FSA cards accepted on Garmin.com
The compromises
- Body fat, muscle, bone and water are impedance estimates that shift with hydration and time of day, under the manual's own two-hour and same-conditions protocol
- Every extra user needs a Garmin Connect account and a connection to the owner, and Garmin says people with pacemakers or other internal electronic devices should not use the scale
- The extra $70 over the Withings Body Smart buys slots and Garmin Connect; the Withings also estimates from foot-to-foot impedance and has its own color screen, and Garmin's battery quote runs six months shorter
What we have not verified: The weighing-range and accuracy figures come from the Japanese manual's spec table; the English manual prints load, battery and temperature only. No independent reference-method test of the Index S2's impedance accuracy was consulted. Amazon itself was the seller at $199.99 on 2026-09-27, the same price as Garmin.com.
The things in this guide
A closer look at the products, who they may suit, and what to check before buying.
Index S2
$199.99 buys Wi-Fi uploads with no phone in the room, 16 user profiles, a 30-day weight trend and weather on the display, and up to nine months from four AAA batteries.
Before you buy: The composition figures are impedance estimates that need repeatable conditions, Garmin says people with pacemakers or other internal electronic devices should not use it, and the Withings covers Wi-Fi and the same kind of estimate for $70 less.
Price checked September 27, 2026. Retailer prices can change.Weight is measured; the rest is estimated
Step on barefoot and the Index S2 weighs you, then moves through the other numbers on the display every few seconds. BMI is arithmetic on your profile height. Body fat, skeletal muscle mass, bone mass and body water come from the foot-to-foot impedance signal, and the manual's word for what that signal produces is estimate.
The manual also prints the protocol that makes estimates comparable: the same circumstances, roughly the same time of day, and a two-hour wait after eating, drinking, exercising, bathing or a sauna, since those change the body's weight, hydration and water distribution. Garmin's spec list adds a hard limit: individuals with pacemakers or other internal electronic devices should not use the Index S2 at all.
Wi-Fi, the screen and the batteries
Set up once through Garmin Connect and the scale uploads over 2.4 GHz Wi-Fi by itself, so no phone has to be in the room. The color display adds a 30-day weight trend graph and a weather widget, and the Garmin Connect app sets which widgets and figures appear when you step on.
Four AAA batteries last up to nine months, according to the manual. The Japanese manual's spec table gives a 5 to 180 kg range in 200 g steps, accurate to +/-400 g up to 90 kg and +/-600 g above; the English spec page lists a 400 lb maximum load. For the most accurate weight, Garmin's instructions call for a hard, flat floor.
Sixteen users, one bathroom
The Index S2 holds sixteen user profiles and shows your initials once it has recognized you, which is the cue to step off. Setting that up is paperwork: only the owner can invite, up to fifteen people, and each of them needs a Garmin Connect account and has to be a Garmin Connect connection of the owner before the scale will take their weigh-ins.
Sixteen is double the Withings Body Smart's eight, which matters for a household of more than eight weighers and not for a couple. Anyone who only wants weight can switch off the composition figures they do not want recorded.
The $70 question
Against the $129.95 Withings Body Smart, the $70 premium buys neither the connection nor the measurement: both scales sync over Wi-Fi and estimate composition from foot-to-foot impedance, with Withings describing its current as multi-frequency. The Withings also lists a 2.8-inch, 320 x 240 color LCD of its own. What the money does buy is eight more user slots, the 30-day trend and weather widgets, and Garmin Connect in place of the Withings app, with Garmin's one-year consumer warranty.
The Withings has its own extras: standing heart rate and basal metabolic rate among its metrics, Athlete, Pregnancy, Baby and Eyes Closed modes, and a 15-month average battery life against Garmin's nine. Buy the Withings when the household fits in eight profiles or those modes matter. Buy the Index S2 when your runs and rides already land in Garmin Connect, or more than eight people share the bathroom. Either way, weigh at the same hour each day.
How we put this together
Built from the product pages and listings below, without test scores or results we have not measured. Specifications and prices change, so check the original page for the exact model, current price, delivery, and returns.
- Garmin: Index S2 product page (opens in a new tab)
- Garmin Index S2 owner's manual: Specifications (opens in a new tab)
- Garmin Index S2 owner's manual: Measurements (opens in a new tab)
- Garmin Index S2 owner's manual (Japanese): specifications table (opens in a new tab)
- Garmin: Consumer Limited Warranty (opens in a new tab)
- Withings: Body Smart (black) product page (opens in a new tab)
- Amazon: Garmin Index S2 listing (ASIN B08KC5V33R) (opens in a new tab)
- Garmin Index S2 owner's manual: Additional Users (opens in a new tab)
- Garmin Index S2 owner's manual: Reading and Recording Measurements (opens in a new tab)
