Samsung Galaxy Watch Ultra vs Xiaomi Watch S3 eSIM
Size, specs & wrist fit compared
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Which one fits you
Both need much the same wrist — roughly 49–68mm across the flat of the wrist. Neither will fit where the other won't, so decide on thickness, weight and features instead.
The Samsung Galaxy Watch Ultra and Xiaomi Watch S3 eSIM share a near-identical 47.4mm case, so wrist presence comes down to thickness, lug-to-lug and weight.
On the wrist the Xiaomi Watch S3 eSIM feels lighter (44g vs 60.5g, case only).
The Samsung Galaxy Watch Ultra is thinner than 87% of the 85 47mm watches we hold thickness for, the Xiaomi Watch S3 eSIM than 76% — so both wear flatter than their widths suggest.
The Samsung Galaxy Watch Ultra is 0.4mm wider, 0.4mm longer, 0.1mm thicker and 16.5g heavier than the Xiaomi Watch S3 eSIM. Both are circular.
Samsung
Galaxy Watch Ultra
Xiaomi
Watch S3 eSIM
Switch or add watches
Samsung
Galaxy Watch Ultra
Xiaomi
Watch S3 eSIM
Watch Fit Tool
For sports watches, lug-to-lug (L2L) is what matters most — it decides whether a watch overhangs your wrist. Bulky is fine; overhang is not.
Measure at the point where you wear your watch — typically just below the wrist bone.
Flat width — lay your arm on a table, palm facing up, and measure straight across the top of your wrist with a ruler. Bone to bone; do not follow the curve down the sides.
Around — wrap a tape measure snugly round the wrist. No tape? Wrap a strip of paper, mark the overlap and hold the strip against a ruler.
Width ≠ circumference. They are different numbers — around 170mm is about 64mm across — so set the toggle to whichever one you actually measured before you type it in.
Samsung Galaxy Watch Ultra
Case 47.4mm · Lug-to-lug 47.4mm · Thickness 12.1mm · 61g
Sweet Spot
47.4mm on a 55mm wrist
Across the wrist it works — 3.8mm spare each side — but wide enough that the edge of the case back lifts clear of the skin.
On a 55mm wrist the sweet spot is 47–53mm lug to lug. This one is 47.4mm.
Measure where you wear it, just below the wrist bone. Either of these works — the tool converts between them.
- 1. Flat width — arm flat on a table, palm up. Measure straight across the top of the wrist, bone to bone, ignoring the curve down the sides.
- 2. Around — a tape, or a strip of paper marked and held against a ruler, snug the whole way round.
Leather: Attaches at the lugs, so the case back rests on your skin. Thins and softens with wear. Typical figures, not this model’s own.
Show the measurementsHide the measurements
- Across the wrist3.8mm spare each side
Fills the wrist without reaching the edge.
- Off the wrist12.1mm off the skin
Normal sports-watch height for a wrist this size. (12.1mm case, back against the skin)
- How it seats~6.3mm under the rim
Wide enough that the edge of the case back lifts clear of the skin.
- Weight on the wrist61g
Substantial without being a burden — the usual weight of a steel watch on a wrist this size. (1.1g per mm of wrist)
Xiaomi Watch S3 eSIM
Case 47.0mm · Lug-to-lug 47.0mm · Thickness 12.0mm · 44g
Sweet Spot
47mm on a 55mm wrist
Across the wrist it works — 4.0mm spare each side — but wide enough that the edge of the case back lifts clear of the skin.
On a 55mm wrist the sweet spot is 47–53mm lug to lug. This one is 47mm.
Measure where you wear it, just below the wrist bone. Either of these works — the tool converts between them.
- 1. Flat width — arm flat on a table, palm up. Measure straight across the top of the wrist, bone to bone, ignoring the curve down the sides.
- 2. Around — a tape, or a strip of paper marked and held against a ruler, snug the whole way round.
Leather: Attaches at the lugs, so the case back rests on your skin. Thins and softens with wear. Typical figures, not this model’s own.
Show the measurementsHide the measurements
- Across the wrist4.0mm spare each side
Fills the wrist without reaching the edge.
- Off the wrist12.0mm off the skin
Normal sports-watch height for a wrist this size. (12.0mm case, back against the skin)
- How it seats~6.1mm under the rim
Wide enough that the edge of the case back lifts clear of the skin.
- Weight on the wrist44g
Light enough to forget you have it on. (0.8g per mm of wrist)
2D Dimension Schematics
Every case drawn to scale on a shared centre — from above, and in profile against the wrist.
- Samsung Galaxy Watch Ultra47.4mm · 12.1mm thick
- Xiaomi Watch S3 eSIM47mm · 12mm thick
3D preview
Samsung Galaxy Watch Ultra vs Xiaomi Watch S3 eSIM 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 Training mode, where the Samsung Galaxy Watch Ultra lasts 16.0× as long as the Xiaomi Watch S3 eSIM (2 days against 3 hours).
Samsung Galaxy Watch UltraXiaomi Watch S3 eSIM
Smartwatch
4 days15 daysBattery Saver
100 hours—Training
48 hours3 hoursGPS
—3 hours
Specifications
The short version
10 key specs| Spec | SamsungGalaxy Watch Ultra | XiaomiWatch S3 eSIM |
|---|---|---|
| Case Width | 47.4mm | 47mm |
| Thickness | 12.1mm | 12mm |
| Weight | 60.5g | 44g |
| Shape | Circular | Circular |
| Water Resistance | 10 ATM | 5 ATM |
| GPS | Yes | Yes |
| Display type | OLED/AMOLED | OLED/AMOLED |
| Screen size | 1.5 inches | 1.43 inches |
| Battery life | 4 days | 15 days |
| Released | 2024 | 2023 |
Every specification
121 specs| Spec | Samsung Galaxy Watch Ultra | Xiaomi Watch S3 eSIM |
|---|---|---|
| Design | ||
| width | 47.4 | 47 |
| height | 47.4 | 47 |
| volume | 27.19 cm³ | 26.51 cm³ |
| weight | 60.5 g | 44 g |
| thickness | 12.1 | 12 |
| ATM rating | 10 ATM | 5 ATM |
| resolution | 480 x 480 px | 466 x 466 px |
| screen size | 1.5 inches | 1.43 inches |
| Display type | OLED/AMOLED | OLED/AMOLED |
| Has a display | Yes | Yes |
| pixel density | 327 ppi | 326 ppi |
| maximum altitude | 29527 feet | — |
| water resistance | Waterproof | Waterproof |
| Always-On Display | Yes | Yes |
| has a touch screen | Yes | Yes |
| is designed for kids | No | No |
| waterproof depth rating | 100 m | 50 m |
| Watch band is replaceable | Yes | Yes |
| Has sapphire glass display | Yes | No |
| maximum operating temperature | 55 °C | — |
| Ingress Protection (IP) rating | IP68 | — |
| has branded damage-resistant glass | No | No |
| lowest potential operating temperature | -20 °C | — |
| Battery | ||
| battery life | 4 days | 15 days |
| battery power | 590 mAh | 486 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 |
| battery life in training mode | 48 hours | 3 hours |
| battery life in power save mode | 100 hours | — |
| battery life with GPS on | — | 3 hours |
| 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 | No |
| Monitors blood oxygenation levels | Yes | Yes |
| Features | ||
| RAM | 2GB | — |
| release date | 2024-07-10 | 2023-10-26 |
| Has a stopwatch | Yes | Yes |
| Has smart alarm | No | No |
| Has call control | Yes | Yes |
| Has silent alarm | Yes | Yes |
| has HRV tracking | Yes | — |
| internal storage | 32GB | — |
| measures VO2 max | Yes | — |
| Has notifications | Yes | Yes |
| Has ECG technology | Yes | No |
| Locates your phone | Yes | Yes |
| has a front camera | No | — |
| has fall detection | Yes | Yes |
| has voice commands | Yes | Yes |
| Acquires GPS faster | Yes | Yes |
| Has vibrating alerts | Yes | Yes |
| shows readiness level | Yes | — |
| Can be used to answer calls | Yes | Yes |
| measures resting heart rate | Yes | Yes |
| has irregular heart rate warnings | Yes | Yes |
| has fast/slow heart rate notifications | Yes | Yes |
| Has a built-in camera remote control function | Yes | Yes |
| warranty period | — | 1 years |
| number of microphones | — | 1 |
| Connectivity | ||
| has NFC | Yes | Yes |
| SIM cards | 1 eSIM | 1 eSIM |
| Wi-Fi version | Wi-Fi 4 (802.11n), Wi-Fi 5 (802.11ac) | — |
| supports ANT+ | No | No |
| supports Wi-Fi | Yes | No |
| supports Galileo | Yes | Yes |
| Bluetooth version | 5.4 | 5.2 |
| has a cellular module | Yes | Yes |
| Is compatible with iOS | No | Yes |
| Is compatible with Android | Yes | Yes |
| Miscellaneous | ||
| Has passcode | Yes | No |
| 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 | Yes |
| Compatible with external heart rate monitors | Yes | Yes |
| App & Software | ||
| Ad-free | Yes | — |
| Free app | Yes | Yes |
| Tracks BMI | Yes | — |
| Has coaching | Yes | Yes |
| Includes maps | Yes | — |
| Supports routes | Yes | Yes |
| Has achievements | Yes | Yes |
| Has goal setting | Yes | Yes |
| Has exercise diary | Yes | Yes |
| Predicts ovulation | 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 | No |
| Provides activity reports | Yes | Yes |
| Displays fertile window notifications | Yes | Yes |
| Counts how many calories you've burned | Yes | Yes |
| Doesn’t require account | — | No |
| Activity tracking | ||
| Measures pace | Yes | Yes |
| Tracks distance | Yes | Yes |
| Tracks elevation | Yes | Yes |
| 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 | Yes | — |
| Tracks calorie intake | Yes | Yes |
| Provides sleep reports | Yes | Yes |
| Detects activities automatically | Yes | Yes |
| Has a stroke counter for swimming | Yes | No |
| Designed for golf | — | No |
Wrist Fit
Samsung Galaxy Watch Ultra
Sits best on wrists ~50–68mm wide (≈ 13.4–18.2cm circumference).
Xiaomi Watch S3 eSIM
Sits best on wrists ~49–67mm wide (≈ 13.1–17.9cm circumference).
Frequently Asked Questions
Is the Samsung Galaxy Watch Ultra bigger than the Xiaomi Watch S3 eSIM?
The Samsung Galaxy Watch Ultra is bigger — 47.4mm vs 47mm case width.
Which fits a smaller wrist better, the Samsung Galaxy Watch Ultra or the Xiaomi Watch S3 eSIM?
The Samsung Galaxy Watch Ultra suits wrists around 50–68mm wide, and the Xiaomi Watch S3 eSIM around 49–67mm. The one with the smaller lower bound is the safer pick for a small wrist.
Can I see the Samsung Galaxy Watch Ultra and Xiaomi Watch S3 eSIM 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.