vs
8.3Display5.3
6.9Battery life3.1
4.9Health tracking4.9
9.4Sports & outdoor2.7
8.4Build & durability3.5
Dimensions
Size comparison
T-Rex 3Forerunner 165
| T-Rex 3 | Forerunner 165 | Difference | |
|---|---|---|---|
| Height | 48.5 mm | 43 mm | +5.5 mm |
| Width | 48.5 mm | 43 mm | +5.5 mm |
| Thickness | 13.8 mm | 11.6 mm | +2.2 mm |
| Weight | 68 g | 39 g | +29 g |
Drawn to the same scale from the official dimensions (front and side).
Why is T-Rex 3 better than Forerunner 165?
- Battery life (smartwatch mode)27 days vs 11 days2.5×
- GPS battery life28 h vs 19 h+47%
- Water resistance10 ATM vs 5 ATM2×
- Sport profiles170 vs 256.8×
- Screen size1.5″ vs 1.2″+25%
- Battery saver mode40 days vs 20 days2×
- Resolution (width)480 px vs 390 px+23%
Why is Forerunner 165 better than T-Rex 3?
- Weight68.3 g vs 39 g+75%
- Thickness13.8 mm vs 11.6 mm+19%
Specifications
Side by side
| Design & durability | ||
| Case size | 48 mm | 43 mm |
| Weight | 68.3 g | 39 g |
| Thickness | 13.8 mm | 11.6 mm |
| Height | 48.5 mm | 43 mm |
| Width | 48.5 mm | 43 mm |
| Case material | Stainless steel | Plastic / polymer |
| Sapphire crystal | — | No |
| Lens / cover glass | Gorilla Glass | chemically strengthened glass |
| Strap material | — | silicone |
| Water resistance | 10 ATM | 5 ATM |
| Water rating (maker) | — | 5 ATM |
| Display | ||
| Screen size | 1.5″ | 1.2″ |
| Display technology | AMOLED | AMOLED |
| Panel | AMOLED | AMOLED |
| AMOLED / OLED display | Yes | Yes |
| Always-on display | — | Yes |
| Touchscreen | Yes | Yes |
| Resolution (width) | 480 px | 390 px |
| Resolution (height) | 480 px | 390 px |
| Pixel density | 322 ppi | 325 ppi |
| Battery | ||
| Battery life (smartwatch mode) | 27 days | 11 days |
| Battery saver mode | 40 days | 20 days |
| GPS battery life | 28 h | 19 h |
| GPS battery life (dual-band) | 42 h | — |
| Battery capacity | 700 mAh | — |
| Battery type | — | Lithium ion |
| Wireless charging | — | No |
| Charging | Magnetic charging base | Garmin proprietary plug charger |
| Health sensors | ||
| Optical heart rate | Yes | Yes |
| Blood oxygen (SpO2) | Yes | Yes |
| Temperature sensor | Yes | Yes |
| HRV tracking | — | Yes |
| Sleep tracking | Yes | Yes |
| Sensors | — | GPS, GLONASS, Galileo, Elevate wrist heart rate monitor, Pulse Ox blood oxygen saturation monitor, Barometric altimeter, Compass, Accelerometer, Thermometer, Ambient light sensor |
| Sports & navigation | ||
| Built-in GPS | Yes | Yes |
| Dual-band GPS | Yes | — |
| Satellite systems | — | GLONASS, GALILEO |
| Offline maps | Yes | — |
| Barometric altimeter | Yes | Yes |
| Compass | Yes | Yes |
| Sport profiles | 170 | 25 |
| Connectivity | ||
| NFC payments | — | Yes |
| Wi-Fi | Wi-Fi 4 | — |
| Bluetooth | 5.2 | — |
| ANT+ sensors | — | Yes |
| Smart features | ||
| Calls from the wrist | Yes | — |
| Microphone | Yes | — |
| Voice assistant | Yes | — |
| Music on the watch | Yes | — |
| Storage | — | 4 GB |
| Third-party apps | — | Yes |
| Platform | ||
| Operating system | — | Garmin OS |
| Platform | Proprietary | Proprietary |
| Works with | Android, iOS | iOS, Android |
