Device summary

Amazfit

Amazfit T-Rex 3 Pro 44mm

Garmin

Instinct E 45mm

Full specifications

Full specifications
Basic information
Release year20252025
Starting price——
Display size1.3-inch1.2-inch
Dimensions44.8 mm × 44.8 mm × 13.2 mm45.0 mm × 45.0 mm × 14.2 mm
Weight47 g48 g
Front material——
Back material——
Display
Display technologyAMOLEDMIP
Resolution466 × 466176 × 176
Peak brightness3000 nits—
ProtectionSapphire—
Performance
Expandable storageNo—
Battery & charging
Charging standardMagnetic chargingGarmin proprietary clip / USB charging
Battery typeLithium-ionLithium-ion
Rated capacity500 mAh—
Connectivity
CellularGPS / multi-GNSSGPS / multi-GNSS
Wi‑FiWi-Fi—
BluetoothBluetoothBluetooth
NFC—Yes
Build & durability
FrameFiber-reinforced polymer / Grade 5 titanium bezelFiber-reinforced polymer
Ingress protection10 ATM10 ATM

Key differences

The most meaningful measured gaps in size and weight — not an overall winner.

  • Thickness

    Amazfit T-Rex 3 Pro 44mm

    1 mm thinner

  • Display size

    Amazfit T-Rex 3 Pro 44mm

    0.1 in larger display · minor difference

  • Height

    Very similar height

  • Width

    Very similar width

What these size differences mean

Calculated from the dimensions shown, rounded to 0.1 mm and 1 g. Percentages use the smaller measurement as the reference. Fold and rotation settings affect the dimensions compared.

  • Instinct E 45mm is 0.2 mm (0.4% relative to Amazfit T-Rex 3 Pro 44mm) wider. Check this difference against the width of your current device and pocket opening.
  • Instinct E 45mm is 0.2 mm (0.4% relative to Amazfit T-Rex 3 Pro 44mm) taller. This describes the body outline; screen diagonal alone does not tell you the overall size.
  • Instinct E 45mm is 1 mm (7.6% relative to Amazfit T-Rex 3 Pro 44mm) thicker. Cases and camera protrusions can change the clearance you need.
  • Amazfit T-Rex 3 Pro 44mm is 1 g lighter. This is the listed device-weight difference, not a measured comfort rating.

Use these figures to compare physical size. They do not establish one-handed reach, pocket fit, durability or an overall winner.

Sources and measurement notes

Sizometry compares published specifications and calculates differences. These are not hands-on measurements or tests of comfort, performance or pocket fit.

Check the exact model, year, region and configuration on the linked page. References may cover several variants. Folded and unfolded dimensions differ; cases and camera protrusions may change the space a device needs. Drawings share a relative scale and are not calibrated to life size on your screen.

Amazfit T-Rex 3 Pro 44mm vs Instinct E 45mm Size Comparison