Samsung Galaxy Watch8 - LTE · 40mm vs Xiaomi Watch S4 41mm
Size, specs & wrist fit compared
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Which one fits you
On wrists narrower than about 45mm, the Xiaomi Watch S4 41mm is the safer pick — it stays proportionate down to roughly 43mm, where the Samsung Galaxy Watch8 - LTE · 40mm starts to hang over the edge. Above 45mm both sit cleanly, and the Samsung Galaxy Watch8 - LTE · 40mm gives you more presence.
The Xiaomi Watch S4 41mm wears larger than the Samsung Galaxy Watch8 - LTE · 40mm (41.2mm vs 40.4mm case), giving it more wrist presence — and needing a wider wrist to sit cleanly.
The Samsung Galaxy Watch8 - LTE · 40mm is the slimmer of the two (8.6mm vs 9.5mm), so it slides under a cuff more easily.
On the wrist the Samsung Galaxy Watch8 - LTE · 40mm feels lighter (30g vs 32g, case only).
The Samsung Galaxy Watch8 - LTE · 40mm is thinner than 82% of the 40mm watches we track and the Xiaomi Watch S4 41mm than 98% of the 41mm ones — so both wear flatter than their widths suggest.
The Xiaomi Watch S4 41mm is 0.8mm wider, 1.5mm shorter, 0.9mm thicker and 2g heavier than the Samsung Galaxy Watch8 - LTE · 40mm. Both are circular.
Samsung
Galaxy Watch8 - LTE · 40mm
Xiaomi
Watch S4 41mm
Switch or add watches
Samsung
Galaxy Watch8 - LTE · 40mm
Xiaomi
Watch S4 41mm
2D Dimension Schematics
Every case drawn to scale on a shared centre — from above, and in profile against the wrist.
- Samsung Galaxy Watch8 - LTE · 40mm40.4mm × 42.7mm · 8.6mm thick
- Xiaomi Watch S4 41mm41.2mm · 9.5mm thick
3D preview
Samsung Galaxy Watch8 - LTE · 40mm vs Xiaomi Watch S4 41mm on a wrist
Sized to your own wrist, turned any way you like.
Shapes are built from published measurements, not manufacturer 3D models — accurate proportions, generic dial.
Battery life compared
Furthest apart in Smartwatch mode, where the Xiaomi Watch S4 41mm lasts 4.0× as long as the Samsung Galaxy Watch8 - LTE · 40mm (8 days against 2 days).
Samsung Galaxy Watch8 - LTE · 40mmXiaomi Watch S4 41mm
Smartwatch
2 days8 days
Specifications
The short version
11 key specs| Spec | SamsungGalaxy Watch8 - LTE · 40mm | XiaomiWatch S4 41mm |
|---|---|---|
| Case Width | 40.4mm | 41.2mm |
| Lug-to-Lug | 42.7mm | 41.2mm |
| Thickness | 8.6mm | 9.5mm |
| Weight | 30g | 32g |
| Shape | Circular | Circular |
| Water Resistance | 5 ATM | 5 ATM |
| GPS | Yes | Yes |
| Display type | OLED/AMOLED | OLED/AMOLED |
| Screen size | 1.34 inches | 1.32 inches |
| Battery life | 2 days | 8 days |
| Released | 2025 | 2025 |
Every specification
117 specs| Spec | Samsung Galaxy Watch8 - LTE · 40mm | Xiaomi Watch S4 41mm |
|---|---|---|
| Design | ||
| width | 40.4 | 41.2 |
| height | 42.7 | 41.2 |
| volume | 14.84 cm³ | 16.13 cm³ |
| weight | 30 g | 32 g |
| thickness | 8.6 | 9.5 |
| ATM rating | 5 ATM | 5 ATM |
| resolution | 438 x 438 px | 466 x 466 px |
| screen size | 1.34 inches | 1.32 inches |
| Display type | OLED/AMOLED | OLED/AMOLED |
| Has a display | Yes | Yes |
| pixel density | 327 ppi | 320 ppi |
| width of band | 20 mm | — |
| water resistance | Water resistant | Waterproof |
| Always-On Display | Yes | Yes |
| has a touch screen | Yes | Yes |
| is designed for kids | No | No |
| waterproof depth rating | 50 m | — |
| Watch band is replaceable | Yes | Yes |
| Has sapphire glass display | Yes | Yes |
| maximum operating temperature | 35 °C | — |
| Ingress Protection (IP) rating | IP68 | — |
| has branded damage-resistant glass | No | No |
| lowest potential operating temperature | 0 °C | — |
| Battery | ||
| battery life | 2 days | 8 days |
| battery power | 325 mAh | 320 mAh |
| has wireless charging | Yes | No |
| has a removable battery | No | No |
| Has a solar power battery | No | No |
| has a rechargeable battery | Yes | Yes |
| Sensors | ||
| has GPS | Yes | Yes |
| has a compass | Yes | Yes |
| Has a barometer | Yes | Yes |
| has a gyroscope | Yes | Yes |
| Has a cadence sensor | No | No |
| has an accelerometer | Yes | Yes |
| Monitors perspiration | No | No |
| Has a heart rate monitor | Yes | Yes |
| Has a temperature sensor | Yes | Yes |
| Monitors blood oxygenation levels | Yes | Yes |
| Features | ||
| RAM | 2GB | — |
| release date | 2025-07-09 | 2025-06-26 |
| Has a stopwatch | Yes | Yes |
| Has smart alarm | No | No |
| Has call control | Yes | Yes |
| Has silent alarm | Yes | Yes |
| has HRV tracking | Yes | Yes |
| internal storage | 32GB | 32GB |
| measures VO2 max | Yes | Yes |
| Has notifications | Yes | Yes |
| Has ECG technology | Yes | No |
| Locates your phone | Yes | Yes |
| has fall detection | Yes | Yes |
| has voice commands | Yes | Yes |
| Acquires GPS faster | Yes | Yes |
| Has vibrating alerts | Yes | Yes |
| shows readiness level | Yes | Yes |
| Can be used to answer calls | Yes | Yes |
| measures resting heart rate | Yes | Yes |
| has irregular heart rate warnings | Yes | No |
| has fast/slow heart rate notifications | Yes | Yes |
| Has a built-in camera remote control function | Yes | Yes |
| warranty period | — | 1 years |
| has a front camera | — | No |
| number of microphones | — | 1 |
| Connectivity | ||
| has NFC | Yes | Yes |
| SIM cards | 1 eSIM | 1 eSIM |
| Wi-Fi version | Wi-Fi 4 (802.11n) | — |
| supports ANT+ | No | No |
| supports Wi-Fi | Yes | No |
| supports Galileo | Yes | Yes |
| Bluetooth version | 5.3 | 5.4 |
| has a cellular module | Yes | Yes |
| Is compatible with iOS | No | Yes |
| Is compatible with Android | Yes | Yes |
| Miscellaneous | ||
| Has passcode | Yes | Yes |
| Has auto pause | Yes | — |
| Is compatible with Windows | No | No |
| Is compatible with Mac OS X | No | No |
| has an external memory slot | No | No |
| Compatible with smart scales | Yes | — |
| has a battery level indicator | Yes | Yes |
| has a socket for a 3.5 mm audio jack | No | No |
| Compatible with external heart rate monitors | Yes | — |
| App & Software | ||
| Ad-free | Yes | Yes |
| Free app | Yes | Yes |
| Tracks BMI | Yes | — |
| Has coaching | Yes | No |
| Includes maps | Yes | Yes |
| Supports routes | Yes | No |
| Has achievements | Yes | Yes |
| Has goal setting | Yes | Yes |
| Has exercise diary | Yes | Yes |
| Can be personalised | Yes | Yes |
| Has weight tracking | Yes | Yes |
| Predicts start date | Yes | Yes |
| Tracks water intake | Yes | Yes |
| Has inactivity alerts | Yes | Yes |
| Has period notifications | Yes | Yes |
| Has temperature tracking | Yes | Yes |
| Provides activity reports | Yes | Yes |
| Counts how many calories you've burned | Yes | Yes |
| Predicts ovulation | — | Yes |
| Doesn’t require account | — | No |
| Activity tracking | ||
| Measures pace | Yes | Yes |
| Tracks distance | Yes | Yes |
| Tracks elevation | Yes | Yes |
| Designed for golf | No | — |
| Tracks your sleep | Yes | Yes |
| Tracks steps taken | Yes | Yes |
| Designed for diving | No | No |
| Has a route tracker | Yes | Yes |
| Has exercise tagging | Yes | Yes |
| Has multi-sport mode | No | — |
| Tracks calorie intake | Yes | Yes |
| Provides sleep reports | Yes | Yes |
| Detects activities automatically | Yes | Yes |
| Has a stroke counter for swimming | Yes | Yes |
Wrist Fit
Samsung Galaxy Watch8 - LTE · 40mm
Sits best on wrists ~45–61mm wide (≈ 12.0–16.3cm circumference).
Xiaomi Watch S4 41mm
Sits best on wrists ~43–59mm wide (≈ 11.5–15.8cm circumference).
Frequently Asked Questions
Is the Samsung Galaxy Watch8 - LTE · 40mm bigger than the Xiaomi Watch S4 41mm?
The Xiaomi Watch S4 41mm is bigger — 41.2mm vs 40.4mm case width.
Which fits a smaller wrist better, the Samsung Galaxy Watch8 - LTE · 40mm or the Xiaomi Watch S4 41mm?
The Samsung Galaxy Watch8 - LTE · 40mm suits wrists around 45–61mm wide, and the Xiaomi Watch S4 41mm around 43–59mm. The one with the smaller lower bound is the safer pick for a small wrist.
Can I see the Samsung Galaxy Watch8 - LTE · 40mm and Xiaomi Watch S4 41mm side by side at true scale?
Yes — the schematics and photos above show both watches at matched scale, and our fit tool overlays each on your wrist width.