vs
3.4Display3.5
2.7Battery life4.8
2.9Build & durability2.7
Dimensions
Size comparison
Approach S42Forerunner 255
| Approach S42 | Forerunner 255 | Difference | |
|---|---|---|---|
| Height | 43.4 mm | 45.6 mm | −2.2 mm |
| Width | 43.4 mm | 45.6 mm | −2.2 mm |
| Thickness | 11.7 mm | 12.9 mm | −1.2 mm |
| Weight | 43 g | 49 g | −6 g |
Drawn to the same scale from the official dimensions (front and side).
Why is Approach S42 better than Forerunner 255?
- Weight43 g vs 49 g+14%
- Thickness11.7 mm vs 12.9 mm+10%
Why is Forerunner 255 better than Approach S42?
- GPS battery life15 h vs 30 h2×
- Battery life (smartwatch mode)10 days vs 14 days+40%
- Sport profiles5 vs 5811.6×
- Storage0.06 GB vs 4 GB66.7×
- Screen size1.2″ vs 1.3″+8%
- Resolution (width)240 px vs 260 px+8%
Specifications
Side by side
| Design & durability | ||
| Case size | 43 mm | 46 mm |
| Weight | 43 g | 49 g |
| Thickness | 11.7 mm | 12.9 mm |
| Height | 43.4 mm | 45.6 mm |
| Width | 43.4 mm | 45.6 mm |
| Case material | — | Plastic / polymer |
| Sapphire crystal | No | No |
| Lens / cover glass | chemically strengthened glass | Corning® Gorilla® Glass 3 |
| Strap material | silicone | silicone |
| Water resistance | 5 ATM | 5 ATM |
| Water rating (maker) | 5 ATM | 5 ATM |
| Display | ||
| Screen size | 1.2″ | 1.3″ |
| 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 |
| Touchscreen | Yes | — |
| Resolution (width) | 240 px | 260 px |
| Resolution (height) | 240 px | 260 px |
| Pixel density | 200 ppi | 200 ppi |
| Battery | ||
| Battery life (smartwatch mode) | 10 days | 14 days |
| GPS battery life | 15 h | 30 h |
| GPS battery life (dual-band) | — | 16 h |
| Battery type | — | Lithium ion |
| Wireless charging | No | No |
| Charging | Garmin proprietary plug charger | Garmin proprietary plug charger |
| Health sensors | ||
| Optical heart rate | — | Yes |
| Blood oxygen (SpO2) | — | Yes |
| Temperature sensor | — | Yes |
| HRV tracking | — | Yes |
| Sleep tracking | — | Yes |
| Sensors | GPS, Gyroscope, Accelerometer | GPS, GLONASS, Galileo, QZSS, BeiDou, SatIQ technology, Elevate wrist heart rate monitor, Pulse Ox blood oxygen saturation monitor, Barometric altimeter, Compass, Gyroscope, Accelerometer, Thermometer |
| Sports & navigation | ||
| Built-in GPS | Yes | Yes |
| Dual-band GPS | — | Yes |
| Satellite systems | — | GLONASS, GALILEO, BDS, QZSS |
| Barometric altimeter | — | Yes |
| Compass | — | Yes |
| Multisport / triathlon mode | — | Yes |
| Sport profiles | 5 | 58 |
| Connectivity | ||
| NFC payments | — | Yes |
| ANT+ sensors | — | Yes |
| Smart features | ||
| Storage | 0.06 GB | 4 GB |
| Third-party apps | — | Yes |
| Platform | ||
| Operating system | Garmin OS | Garmin OS |
| Platform | Proprietary | Proprietary |
| Works with | iOS, Android | iOS, Android |
