Amazfit · 2021
T-Rex ProSize, Dimensions & Wrist Fit
The Amazfit T-Rex Pro sits best on flat wrist widths of about 50–68mm (≈ 13.4–18.2cm wrist circumference). Adjust the slider below to check your wrist.
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The T-Rex Pro in short
The figures that decide whether this watch suits you, pulled out of the full specification sheet further down.
- Between 40 hours and 18 days per charge depending on the power mode — smartwatch at best, gps at worst.
- Water rated to 100 m.
- 13.5mm thick. Thinner than 69% of 48mm watches, so it slides under a cuff more easily than most of its size.
- 1.3 inches OLED/AMOLED display, always-on capable.
- Takes 22mm bands, so third-party straps fit without an adapter.
Does the T-Rex Pro fit your wrist?
Drag the slider to your wrist width and see the T-Rex Pro 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.
Amazfit T-Rex Pro
Case 47.7mm · Lug-to-lug 47.7mm · Thickness 13.5mm · 59g
Sweet Spot
47.7mm on a 55mm wrist
Across the wrist it works — 3.6mm spare each side — but a tall watch on this wrist. Fine over a sleeve, awkward under one.
On a 55mm wrist the sweet spot is 47–53mm lug to lug. This one is 47.7mm.
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 wrist3.6mm spare each side
Fills the wrist without reaching the edge.
- Off the wrist13.5mm off the skin
A tall watch on this wrist. Fine over a sleeve, awkward under one. (13.5mm case, back against the skin)
- How it seats~6.5mm under the rim
Wide enough that the edge of the case back lifts clear of the skin.
- Weight on the wrist59g
Substantial without being a burden — the usual weight of a steel watch on a wrist this size. (1.1g per mm of wrist)
Happy with the fit? Check current availability for the T-Rex Pro.
Check offer2D Dimension Schematics
The T-Rex Pro drawn to scale — from above, and in profile against the wrist.
- Amazfit T-Rex Pro47.7mm · 13.5mm thick
3D preview
Amazfit T-Rex Pro 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.
How long the T-Rex Pro lasts, by power mode
Runtime changes by a factor of 11 depending on what you leave switched on. Bars are scaled against the longest mode.
- Smartwatch18 days
- GPS40 hours
How the T-Rex Pro ranks on battery
Against the 54 Amazfit watches in our database, ranked on each figure Amazfit publishes.
- Everyday use18 days#9 of 54
- GPS tracking40 hours#7 of 29
- Capacity390 mAh#17 of 52
What size band does the T-Rex Pro take?
Lug width
22mm
Any 22mm strap fits, so you are not restricted to Amazfit's own bands. Quick-release pins let you swap without tools — check that a replacement lists 22mm 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.
T-Rex Pro specifications
The figures that decide a purchase, followed by every line Amazfit publishes.
- Battery life
- 18 days
- Display
- 1.3 inches
- Resolution
- 360 x 360 px
- Water rating
- 10 ATM
- Glass
- Gorilla Glass 3
- Strap
- 22 mm
- Charging
- 1.5 hours
Full specification sheet
115 published lines across 8 groups, unedited
Design
- width
- 47.7
- height
- 47.7
- volume
- 30.72 cm³
- weight
- 59.4 g
- thickness
- 13.5
- ATM rating
- 10 ATM
- resolution
- 360 x 360 px
- screen size
- 1.3 inches
- Display type
- OLED/AMOLED
- Has a display
- pixel density
- 391.6 ppi
- width of band
- 22 mm
- water resistance
- Waterproof
- Always-On Display
- has a touch screen
- Gorilla Glass version
- Gorilla Glass 3
- waterproof depth rating
- 100 m
- Watch band is replaceable
- Has sapphire glass display
- maximum operating temperature
- 70 °C
- has branded damage-resistant glass
- lowest potential operating temperature
- -40 °C
Battery
- charge time
- 1.5 hours
- battery life
- 18 days
- battery power
- 390 mAh
- has wireless charging
- has a removable battery
- battery life with GPS on
- 40 hours
- Has a solar power battery
- has a rechargeable battery
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
- release date
- 2021-03-27
- Has a stopwatch
- Has smart alarm
- warranty period
- 1 years
- Has call control
- Has silent alarm
- has HRV tracking
- 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
- 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
- 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 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
- Includes maps
- Supports routes
- Has achievements
- Has goal setting
- Has live tracking
- Has exercise diary
- Predicts ovulation
- Can be personalised
- Has weight tracking
- Predicts start date
- Tracks water intake
- Has inactivity alerts
- Has period notifications
- Has temperature tracking
- Provides activity reports
- Displays fertile window notifications
- 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 T-Rex Pro
Watches that cover a similar amount of wrist, with the measurements that separate them.
Amazfit
Balance 2
- Width
- 47.4mm
- Thick
- 12.3mm
- Weight
- 43g
Amazfit
Pop 2
- Width
- 47.2mm
- Thick
- 12.9mm
- Weight
- 64g
Amazfit
Falcon
- Width
- 47.2mm
- Thick
- 13mm
- Weight
- 64g
Amazfit
GTR
- Width
- 47.2mm
- Thick
- 10.75mm
- Weight
- 48g
Amazfit
Stratos 3
- Width
- 48.6mm
- Thick
- 13.4mm
- Weight
- 40.4g
Amazfit
Active Edge
- Width
- 46.6mm
- Thick
- 12mm
- Weight
- 34g
T-Rex Pro — Frequently Asked Questions
Will the Amazfit T-Rex Pro fit my wrist?
The Amazfit T-Rex Pro looks balanced on flat wrist widths of roughly 50–68mm (about 13.4–18.2cm circumference). Drag the slider above to check it against your own measurement.
What size band does the Amazfit T-Rex Pro take?
22mm. Any 22mm strap fits, so you are not limited to Amazfit's own bands — look for a quick-release fitting if you want to swap without tools.
How long does the Amazfit T-Rex Pro battery last?
Between 40 hours and 18 days per charge, depending on the power mode. Amazfit rates Smartwatch at 18 days and GPS at 40 hours; the chart above lists all 2 modes.
How does the Amazfit T-Rex Pro battery compare with other Amazfit watches?
At 18 days in everyday use it ranks #9 of the 54 Amazfit watches in our database — the top 17% of the range. The full ranking, including GPS and power-saving figures, is on our Amazfit battery life comparison.
Is the Amazfit T-Rex Pro thick for a 48mm watch?
At 13.5mm, thinner than 69% of 48mm 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.
What other watches are the same size as the Amazfit T-Rex Pro?
Oppo Watch X2, Huawei Watch 4 Pro, Mobvoi TicWatch Pro 5, ZTE Watch GT all sit within half a millimetre of the Amazfit T-Rex Pro's 47.7mm case, so they cover the same amount of wrist.
