Samsung · 2021
Galaxy Watch 4 - LTE · 40mmSize, Dimensions & Wrist Fit
Case Width
40.4mm
Thickness
9.8mm
Lug-to-Lug
39.3mm
Weight
25.9g
The Samsung Galaxy Watch 4 - LTE · 40mm sits best on flat wrist widths of about 41–56mm (≈ 10.9–15.0cm wrist circumference). Adjust the slider below to check your wrist.
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The Galaxy Watch 4 - LTE · 40mm in short
The figures that decide whether this watch suits you, pulled out of the full specification sheet further down.
- Between 40 hours and 2 days per charge depending on the power mode — smartwatch at best, battery saver at worst.
- Water rated to 50 m.
- 25.9g on the wrist. Lighter than 98% of the 40mm watches we have weights for.
- 1.2 inches OLED/AMOLED display, always-on capable.
- Takes 20mm bands, so third-party straps fit without an adapter.
Does the Galaxy Watch 4 - LTE · 40mm fit your wrist?
Drag the slider to your wrist width and see the Galaxy Watch 4 - LTE · 40mm overlaid at true scale. Lug-to-lug — not case diameter — decides whether a watch overhangs your wrist.
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 4 - LTE · 40mm
Case 40.4mm · Lug-to-lug 40.4mm · Thickness 9.8mm · 26g
Balanced Fit
40.4mm 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 40.4mm, 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 wrist7.3mm spare each side
Comfortable, with visible skin either side.
- Off the wrist9.8mm off the skin
Normal sports-watch height for a wrist this size. (9.8mm 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 wrist26g
Light enough to forget you have it on. (0.5g per mm of wrist)
Happy with the fit? Check current availability for the Galaxy Watch 4 - LTE · 40mm.
Check offer2D Dimension Schematics
The Galaxy Watch 4 - LTE · 40mm drawn to scale — from above, and in profile against the wrist.
- Samsung Galaxy Watch 4 - LTE · 40mm40.4mm × 39.3mm · 9.8mm thick
3D preview
Samsung Galaxy Watch 4 - LTE · 40mm on a wrist
On an arm sized to your own wrist — the view a product photo never gives you.
Shapes are built from published measurements, not manufacturer 3D models — accurate proportions, generic dial.
Which Galaxy Watch 4 - LTE size fits you?
This model comes in 2 versions. Set your measurement and each one reports its own verdict — tap any size to open its page.
Which of these fits your wrist?
Roughly a 14.7cm wrist circumference — the measurement a tape gives you. Compared against lug-to-lug where we have it, case width otherwise.
All 2 Galaxy Watch 4 - LTE variants fit this wrist. The 44.4mm · LTE gives you the most presence without overhanging; the smallest is the discreet end of the range.
- Width
- 40.4mm
- Thick
- 9.8mm
- Weight
- 25.9g
7.9mm clear a side
- Width
- 44.4mm
- Thick
- 9.8mm
- Weight
- 30.3g
5.9mm clear a side
View this sizeHow long the Galaxy Watch 4 - LTE · 40mm lasts, by power mode
Runtime changes by a factor of 1 depending on what you leave switched on. Bars are scaled against the longest mode.
- Smartwatch2 days
- Battery Saver40 hours
How the Galaxy Watch 4 - LTE · 40mm ranks on battery
Against the 64 Samsung watches in our database, ranked on each figure Samsung publishes.
- Everyday use2 days#20 of 64
- Power save40 hours#8 of 11
- Capacity247 mAh#51 of 64
What size band does the Galaxy Watch 4 - LTE · 40mm take?
Lug width
20mm
Any 20mm strap fits, so you are not restricted to Samsung's own bands. Quick-release pins let you swap without tools — check that a replacement lists 20mm and quick-release before buying.
Affiliate disclosure: As an Amazon Associate, WatchFitTool earns from qualifying purchases. If you buy through links on this page, we may earn a commission at no extra cost to you. Learn more.
Galaxy Watch 4 - LTE · 40mm specifications
The figures that decide a purchase, followed by every line Samsung publishes.
- Battery life
- 2 days
- Display
- 1.2 inches
- Resolution
- 396 x 396 px
- Water rating
- 5 ATM
- Glass
- Gorilla Glass DX+
- Strap
- 20 mm
- Storage
- 16GB
- Charging
- 2 hours
Full specification sheet
117 published lines across 8 groups, unedited
Design
- width
- 40.4
- height
- 39.3
- volume
- 15.56 cm³
- weight
- 25.9 g
- thickness
- 9.8
- ATM rating
- 5 ATM
- resolution
- 396 x 396 px
- screen size
- 1.2 inches
- Display type
- OLED/AMOLED
- Has a display
- pixel density
- 455 ppi
- width of band
- 20 mm
- water resistance
- Waterproof
- Always-On Display
- has a touch screen
- Gorilla Glass version
- Gorilla Glass DX+
- waterproof depth rating
- 50 m
- Watch band is replaceable
- Has sapphire glass display
- Ingress Protection (IP) rating
- IP68
- has branded damage-resistant glass
Battery
- charge time
- 2 hours
- battery life
- 2 days
- battery power
- 247 mAh
- has wireless charging
- has a removable battery
- Has a solar power battery
- has a rechargeable battery
- battery life in power save mode
- 40 hours
Sensors
- has GPS
- has a compass
- Has a barometer
- has a gyroscope
- Has a cadence sensor
- has an accelerometer
- Monitors perspiration
- Has a heart rate monitor
- Has a temperature sensor
- Monitors blood oxygenation levels
Features
- RAM
- 1.5GB
- CPU speed
- 2 x 1.18 GHz
- release date
- 2021-08-11
- Has a stopwatch
- Has smart alarm
- warranty period
- 1 years
- Has call control
- Has silent alarm
- has HRV tracking
- internal storage
- 16GB
- measures VO2 max
- Has notifications
- Has ECG technology
- Locates your phone
- has a front camera
- has fall detection
- has voice commands
- Acquires GPS faster
- Has vibrating alerts
- number of microphones
- 1
- shows readiness level
- Can be used to answer calls
- measures resting heart rate
- has irregular heart rate warnings
- has fast/slow heart rate notifications
- Has a built-in camera remote control function
Connectivity
- has NFC
- SIM cards
- 1 eSIM
- Wi-Fi version
- Wi-Fi 4 (802.11n)
- supports ANT+
- supports Wi-Fi
- supports Galileo
- Bluetooth version
- 5
- has a cellular module
- Is compatible with iOS
- Is compatible with Android
Miscellaneous
- has aptX
- Has passcode
- Has auto pause
- Is compatible with Windows
- Is compatible with Mac OS X
- has an ambient light sensor
- has an external memory slot
- Compatible with smart scales
- has a battery level indicator
- has a socket for a 3.5 mm audio jack
- Compatible with external heart rate monitors
App & Software
- Ad-free
- Free app
- Tracks BMI
- Has coaching
- Supports routes
- Has achievements
- Has goal setting
- Has exercise diary
- Has weight tracking
- Predicts start date
- Tracks water intake
- Has inactivity alerts
- Has period notifications
- Has temperature tracking
- Doesn’t require account
- Provides activity reports
- Counts how many calories you've burned
Activity tracking
- Measures pace
- Tracks distance
- Tracks elevation
- Designed for golf
- Tracks your sleep
- Tracks steps taken
- Designed for diving
- Has a route tracker
- Has exercise tagging
- Has multi-sport mode
- Tracks calorie intake
- Provides sleep reports
- Detects activities automatically
- Has a stroke counter for swimming
Alternatives to the Galaxy Watch 4 - LTE · 40mm
Watches that cover a similar amount of wrist, with the measurements that separate them.
Samsung
Galaxy Watch8 - LTE · 40mm
- Width
- 40.4mm
- Thick
- 8.6mm
- Weight
- 30g
Samsung
Galaxy Watch8 - Wi-Fi · 40mm
- Width
- 40.4mm
- Thick
- 8.6mm
- Weight
- 30g
Samsung
Galaxy Watch7 - Wi-Fi · 40mm
- Width
- 40.4mm
- Thick
- 9.7mm
- Weight
- 33.8g
Samsung
Galaxy Watch7 - LTE · 40mm
- Width
- 40.4mm
- Thick
- 9.7mm
- Weight
- 33.8g
Samsung
Galaxy Watch 4 - Wi-Fi · 40mm
- Width
- 40.4mm
- Thick
- 9.8mm
- Weight
- 25.9g
Samsung
Galaxy Watch Active2 - Aluminium · 40mm
- Width
- 40mm
- Thick
- 10.9mm
- Weight
- 26g
Galaxy Watch 4 - LTE · 40mm — Frequently Asked Questions
Will the Samsung Galaxy Watch 4 - LTE · 40mm fit my wrist?
The Samsung Galaxy Watch 4 - LTE · 40mm looks balanced on flat wrist widths of roughly 41–56mm (about 10.9–15.0cm circumference). Drag the slider above to check it against your own measurement.
What size band does the Samsung Galaxy Watch 4 - LTE · 40mm take?
20mm. Any 20mm strap fits, so you are not limited to Samsung's own bands — look for a quick-release fitting if you want to swap without tools.
How long does the Samsung Galaxy Watch 4 - LTE · 40mm battery last?
Between 40 hours and 2 days per charge, depending on the power mode. Samsung rates Smartwatch at 2 days and Battery Saver at 40 hours; the chart above lists all 2 modes.
How does the Samsung Galaxy Watch 4 - LTE · 40mm battery compare with other Samsung watches?
At 2 days in everyday use it ranks #20 of the 64 Samsung watches in our database — the top 31% of the range. The full ranking, including GPS and power-saving figures, is on our Samsung battery life comparison.
Is the Samsung Galaxy Watch 4 - LTE · 40mm thick for a 40mm watch?
At 9.8mm, thinner than 66% of 40mm watches, so it slides under a cuff more easily than most of its size. Thickness, not case width, is what decides whether a watch catches on a shirt cuff.
Should I get the 40.4mm or 44.4mm Galaxy Watch 4 - LTE?
The Galaxy Watch 4 - LTE comes in 2 case sizes — 40.4mm, 44.4mm. Which one suits you depends on the flat width of your wrist rather than preference: the larger sizes need a wider wrist to sit inside the edge. Set your measurement in the size picker above and each variant reports its clearance in millimetres.
What other watches are the same size as the Samsung Galaxy Watch 4 - LTE · 40mm?
TAG Heuer Aquaracer Professional 200 Solargraph 40 UK Limited Edition, Xiaomi Redmi Watch 6, Vivo Watch GT 2 - Bluetooth, Huawei Watch Fit 4 Pro all sit within half a millimetre of the Samsung Galaxy Watch 4 - LTE · 40mm's 40.4mm case, so they cover the same amount of wrist.
What is the lug-to-lug of the Samsung Galaxy Watch 4 - LTE · 40mm?
39.3mm, against a 40.4mm case width. Lug-to-lug is the measurement that decides overhang: if it exceeds the flat width of your wrist, the lugs sit past the edge no matter how modest the case diameter looks.
