Fitbit Ace LTE vs Samsung Galaxy Watch8 LTE 40mm
Size, specs & wrist fit compared
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Which one fits you
On wrists narrower than about 47mm, the Samsung Galaxy Watch8 LTE 40mm is the safer pick — it stays proportionate down to roughly 45mm, where the Fitbit Ace LTE starts to hang over the edge. Above 47mm both sit cleanly, and the Fitbit Ace LTE gives you more presence.
The Fitbit Ace LTE wears larger than the Samsung Galaxy Watch8 LTE 40mm (41.04mm 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 13.35mm), so it slides under a cuff more easily.
The Fitbit Ace LTE is middle-of-the-pack for thickness among the 373 41mm watches in the database.
Among the 509 40mm watches we hold thickness for, the Samsung Galaxy Watch8 LTE 40mm is thinner than 83%, so it wears flatter than its width suggests.
The Fitbit Ace LTE is 0.6mm wider, 2.2mm longer, 4.8mm thicker and 2g lighter than the Samsung Galaxy Watch8 LTE 40mm. Both are circular.
Fitbit
Ace LTE
Samsung
Galaxy Watch8 - LTE · 40mm
Switch or add watches
Fitbit
Ace LTE
Samsung
Galaxy Watch8 - LTE · 40mm
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.
Fitbit Ace LTE
Case 41.0mm · Lug-to-lug 44.9mm · Thickness 13.3mm · 28g
Balanced Fit
44.9mm on a 55mm wrist
Comfortably inside the edges of your wrist, and it seats and sits low enough to wear without thinking about it.
On a 55mm wrist the sweet spot is 47–53mm lug to lug. This one is 44.9mm, so you could go bigger.
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 wrist5.1mm spare each side
Comfortable, with visible skin either side.
- Off the wrist13.3mm off the skin
Normal sports-watch height for a wrist this size. (13.3mm case, back against the skin)
- How it seats~3.7mm under the rim
Seats well, with the case back following most of the wrist.
- Weight on the wrist28g
Light enough to forget you have it on. (0.5g per mm of wrist)
Samsung Galaxy Watch8 - LTE · 40mm
Case 40.4mm · Lug-to-lug 42.7mm · Thickness 8.6mm · 30g
Balanced Fit
42.7mm on a 55mm wrist
Comfortably inside the edges of your wrist, and it seats and sits low enough to wear without thinking about it.
On a 55mm wrist the sweet spot is 47–53mm lug to lug. This one is 42.7mm, so you could go bigger.
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 wrist6.1mm spare each side
Comfortable, with visible skin either side.
- Off the wrist8.6mm off the skin
Sits low enough to disappear under a cuff. (8.6mm case, back against the skin)
- How it seats~3.5mm under the rim
Seats well, with the case back following most of the wrist.
- Weight on the wrist30g
Light enough to forget you have it on. (0.5g per mm of wrist)
2D Dimension Schematics
Every case drawn to scale on a shared centre — from above, and in profile against the wrist.
- Fitbit Ace LTE41mm × 44.9mm · 13.3mm thick
- Samsung Galaxy Watch8 - LTE · 40mm40.4mm × 42.7mm · 8.6mm thick
3D preview
Fitbit Ace LTE vs Samsung Galaxy Watch8 - LTE · 40mm 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 Fitbit Ace LTE lasts 8.0× as long as the Samsung Galaxy Watch8 LTE 40mm (16 days against 2 days).
Fitbit Ace LTESamsung Galaxy Watch8 LTE 40mm
Smartwatch
16 days2 days
Specifications
The short version
11 key specs| Spec | FitbitAce LTE | SamsungGalaxy Watch8 - LTE · 40mm |
|---|---|---|
| Case Width | 41.04mm | 40.4mm |
| Lug-to-Lug | 44.89mm | 42.7mm |
| Thickness | 13.35mm | 8.6mm |
| Weight | 28.03g | 30g |
| Shape | Circular | Circular |
| Water Resistance | 5 ATM | 5 ATM |
| GPS | Yes | Yes |
| Display type | OLED/AMOLED | OLED/AMOLED |
| Screen size | 1.61 inches | 1.34 inches |
| Battery life | 16 days | 2 days |
| Released | 2024 | 2025 |
Every specification
118 specs| Spec | Fitbit Ace LTE | Samsung Galaxy Watch8 - LTE · 40mm |
|---|---|---|
| Design | ||
| width | 41.04 | 40.4 |
| height | 44.89 | 42.7 |
| volume | 24.59 cm³ | 14.84 cm³ |
| weight | 28.03 g | 30 g |
| thickness | 13.35 | 8.6 |
| ATM rating | 5 ATM | 5 ATM |
| screen size | 1.61 inches | 1.34 inches |
| Display type | OLED/AMOLED | OLED/AMOLED |
| Has a display | Yes | Yes |
| pixel density | 333 ppi | 327 ppi |
| water resistance | Water resistant | Water resistant |
| Always-On Display | Yes | Yes |
| has a touch screen | Yes | Yes |
| is designed for kids | Yes | No |
| Gorilla Glass version | Gorilla Glass 3 | — |
| Watch band is replaceable | Yes | Yes |
| Has sapphire glass display | No | Yes |
| has branded damage-resistant glass | Yes | No |
| resolution | — | 438 x 438 px |
| width of band | — | 20 mm |
| waterproof depth rating | — | 50 m |
| maximum operating temperature | — | 35 °C |
| Ingress Protection (IP) rating | — | IP68 |
| lowest potential operating temperature | — | 0 °C |
| Battery | ||
| charge time | 1.16 hours | — |
| battery life | 16 days | 2 days |
| battery power | 328 mAh | 325 mAh |
| has wireless charging | No | Yes |
| 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 | No | 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 | No | Yes |
| Monitors blood oxygenation levels | Yes | Yes |
| Features | ||
| RAM | 2GB | 2GB |
| release date | 2024-05-29 | 2025-07-09 |
| Has a stopwatch | Yes | Yes |
| Has smart alarm | No | No |
| warranty period | 1 years | — |
| Has call control | Yes | Yes |
| Has silent alarm | Yes | Yes |
| has HRV tracking | No | Yes |
| internal storage | 32GB | 32GB |
| measures VO2 max | No | Yes |
| Has notifications | Yes | Yes |
| Has ECG technology | No | Yes |
| has a front camera | No | — |
| has fall detection | No | Yes |
| has voice commands | No | Yes |
| Has vibrating alerts | Yes | Yes |
| number of microphones | 1 | — |
| shows readiness level | No | Yes |
| Can be used to answer calls | Yes | Yes |
| measures resting heart rate | Yes | Yes |
| has irregular heart rate warnings | No | Yes |
| has fast/slow heart rate notifications | Yes | Yes |
| Locates your phone | — | Yes |
| Acquires GPS faster | — | Yes |
| Has a built-in camera remote control function | — | Yes |
| Connectivity | ||
| has NFC | Yes | Yes |
| SIM cards | 1 eSIM | 1 eSIM |
| Wi-Fi version | Wi-Fi 4 (802.11n) | Wi-Fi 4 (802.11n) |
| supports ANT+ | No | No |
| supports Wi-Fi | Yes | Yes |
| supports Galileo | Yes | Yes |
| Bluetooth version | 5 | 5.3 |
| has a cellular module | Yes | Yes |
| Is compatible with iOS | Yes | No |
| Is compatible with Android | Yes | Yes |
| Miscellaneous | ||
| Has passcode | Yes | Yes |
| Has auto pause | Yes | 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 | 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 | Yes |
| App & Software | ||
| Ad-free | Yes | Yes |
| Free app | Yes | Yes |
| Has achievements | Yes | Yes |
| Has goal setting | Yes | Yes |
| Has exercise diary | Yes | Yes |
| Predicts ovulation | 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 | No | Yes |
| Provides activity reports | Yes | Yes |
| Counts how many calories you've burned | Yes | Yes |
| Tracks BMI | — | Yes |
| Has coaching | — | Yes |
| Includes maps | — | Yes |
| Supports routes | — | Yes |
| Activity tracking | ||
| Measures pace | Yes | Yes |
| Tracks distance | Yes | Yes |
| Tracks elevation | Yes | Yes |
| Designed for golf | No | 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 | No |
| Tracks calorie intake | Yes | Yes |
| Provides sleep reports | Yes | Yes |
| Detects activities automatically | Yes | Yes |
| Has a stroke counter for swimming | No | Yes |
Wrist Fit
Fitbit Ace LTE
Sits best on wrists ~47–64mm wide (≈ 12.6–17.1cm circumference).
Samsung Galaxy Watch8 LTE 40mm
Sits best on wrists ~45–61mm wide (≈ 12.0–16.3cm circumference).
Frequently Asked Questions
Is the Fitbit Ace LTE bigger than the Samsung Galaxy Watch8 LTE 40mm?
The Fitbit Ace LTE is bigger — 41.04mm vs 40.4mm case width.
Which fits a smaller wrist better, the Fitbit Ace LTE or the Samsung Galaxy Watch8 LTE 40mm?
The Fitbit Ace LTE suits wrists around 47–64mm wide, and the Samsung Galaxy Watch8 LTE 40mm around 45–61mm. The one with the smaller lower bound is the safer pick for a small wrist.
Can I see the Fitbit Ace LTE and Samsung Galaxy Watch8 LTE 40mm 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.