vs
2.2Display2.4
3.7Battery life2.1
3.5Build & durability3.9
Dimensions
Size comparison
Forerunner 255SForerunner 45S
| Forerunner 255S | Forerunner 45S | Difference | |
|---|---|---|---|
| Height | 41 mm | 39.5 mm | +1.5 mm |
| Width | 41 mm | 39.5 mm | +1.5 mm |
| Thickness | 12.4 mm | 11.4 mm | +1 mm |
| Weight | 39 g | 32 g | +7 g |
Drawn to the same scale from the official dimensions (front and side).
Why is Forerunner 255S better than Forerunner 45S?
- Battery life (smartwatch mode)12 days vs 7 days+71%
- GPS battery life26 h vs 13 h2×
- Sport profiles58 vs 96.4×
- Screen size1.1″ vs 1.04″+6%
- Resolution (width)218 px vs 208 px+5%
Why is Forerunner 45S better than Forerunner 255S?
- Weight39 g vs 32 g+22%
- Thickness12.4 mm vs 11.4 mm+9%
Specifications
Side by side
| Design & durability | ||
| Case size | 41 mm | 40 mm |
| Weight | 39 g | 32 g |
| Thickness | 12.4 mm | 11.4 mm |
| Height | 41 mm | 39.5 mm |
| Width | 41 mm | 39.5 mm |
| Case material | Plastic / polymer | — |
| Sapphire crystal | No | No |
| Lens / cover glass | Corning® Gorilla® Glass 3 | chemically strengthened glass |
| Strap material | silicone | silicone |
| Water resistance | 5 ATM | 5 ATM |
| Water rating (maker) | 5 ATM | 5 ATM |
| Display | ||
| Screen size | 1.1″ | 1.04″ |
| Display technology | Memory-in-pixel (transflective) | Memory-in-pixel (transflective) |
| Panel | Sunlight-visible, transflective memory-in-pixel | Sunlight-visible, transflective memory-in-pixel |
| AMOLED / OLED display | No | No |
| Always-on display | Yes | Yes |
| Resolution (width) | 218 px | 208 px |
| Resolution (height) | 218 px | 208 px |
| Pixel density | 198 ppi | 200 ppi |
| Battery | ||
| Battery life (smartwatch mode) | 12 days | 7 days |
| GPS battery life | 26 h | 13 h |
| GPS battery life (dual-band) | 13 h | — |
| Battery type | Lithium ion | — |
| Wireless charging | No | No |
| Charging | Garmin proprietary plug charger | Garmin proprietary plug charger |
| Health sensors | ||
| Optical heart rate | Yes | Yes |
| Blood oxygen (SpO2) | Yes | — |
| Temperature sensor | Yes | — |
| HRV tracking | Yes | — |
| Sleep tracking | Yes | Yes |
| Sensors | GPS, GLONASS, Galileo, QZSS, BeiDou, SatIQ technology, Elevate wrist heart rate monitor, Pulse Ox blood oxygen saturation monitor, Barometric altimeter, Compass, Gyroscope, Accelerometer, Thermometer | GPS, GLONASS, Galileo, Elevate wrist heart rate monitor, Accelerometer |
| Sports & navigation | ||
| Built-in GPS | Yes | Yes |
| Dual-band GPS | Yes | — |
| Satellite systems | GLONASS, GALILEO, BDS, QZSS | GLONASS, GALILEO |
| Barometric altimeter | Yes | — |
| Compass | Yes | — |
| Multisport / triathlon mode | Yes | — |
| Sport profiles | 58 | 9 |
| Connectivity | ||
| NFC payments | Yes | — |
| ANT+ sensors | Yes | — |
| Smart features | ||
| Storage | 4 GB | — |
| Third-party apps | Yes | Yes |
| Platform | ||
| Operating system | Garmin OS | Garmin OS |
| Platform | Proprietary | Proprietary |
| Works with | iOS, Android | iOS, Android |
