Garmin Forerunner 55 and Forerunner 45 are basic or entry-level Forerunner watches. For someone looking to buy his or her first Forerunner watch, Forerunner 55 and 45 do provide a good acclimatization experience with the Forerunner range.
Main differences between Forerunner 55 and Forerunner 45
- Forerunner 55 was released in June 2021 and Forerunner 45 was released in April 2019.
- Forerunner 55 costs $199.99 while the Forerunner 45 variant comes at a cost of $139.99.
- The battery backup of the Forerunner 55 is almost double the backup offered by Forerunner 45
- Forerunner 55 has in-built profiles and features for swimming. Forerunner 45 does not have any swimming profiles.
- Forerunner 55 has a higher device storage
- Forerunner 55 has additional outdoor recreation, cycling, training, and running profiles.
We look at these differences in detail below.
Physical specifications
There are few differences in the physical size and dimensions between the Forerunner 55 and 45. We list the product dimensions and specifications of both watches below.
Specifications | Forerunner 55 | Forerunner 45 |
---|---|---|
Watch dimensions | 42 x 42 x 11.6 mm | 42 x 42 x 11.4 mm |
Display diameter | 1.04″ or 26.3 mm | 1.04″ or 26.3 mm |
Display type | MIP (Memory in pixel) | MIP (Memory in pixel) |
Display glass | Chemically strengthened | Chemically strengthened |
Display resolution | 208 x 208 pixels | 208 x 208 pixels |
Weight | 37 g | 36 g |
Device Storage | 200 hours of activity data | 80 hours of activity data |
The striking part of the device attributes is the higher storage of the Forerunner 55 in comparison with the Forerunner 45 smartwatch.

Battery
The battery backup offered by Forerunner 55 is much better than the backup offered by the Forerunner 45 range of running watches. In our opinion, the difference in costs between the Forerunner 55 and 45 can be attributed to the higher battery capacity of the Forerunner 55.
- On the smartwatch mode, Forerunner 55 can go up to 2 weeks and Forerunner 45 can go up to 7 days.
- On the GPS mode, Forerunner 55 can last for up to 20 days and Forerunner 45 can last for up to 13 days.
Essentially, the battery difference is noticeable between the Forerunner 55 and 45.
For people who are serious about running, a Forerunner 55 should become preferable over the Forerunner 45 because of the extended battery backup.
Additional feature differences
There are some basic differences in the features of the Forerunner 55 and Forerunner 45 smartwatches.
- Forerunner 55 offers respiration rate tracking.
- Forerunner 55 does support Women’s Health; Forerunner 45 does not have this feature.
- Forerunner 55 can send relaxation reminders.
- Forerunner 55 can also track hydration levels.
- Forerunner 55 can also send incident detection alerts on the phone. Forerunner 45 does not have this ability.

Main features
Apart from the differences stated above, we review the main features of the Forerunner 55 and Forerunner 45 running watches in the table of comparison below.
Features | Forerunner 55 | Forerunner 45 |
---|---|---|
iOS compatibility | Yes | Yes |
Android compatibility | Yes | Yes |
Watch size | 42 mm | 42 mm |
Display glass | 26.3 mm | 26.3 mm |
Color screen | Yes | Yes |
Touchscreen | No | No |
Water rating | 5 ATM | 5 ATM |
Swim-proof | Yes | Yes |
Swimming profile | Pool swimming | None |
Heart rate monitoring | Yes | Yes |
Daily resting heart rate | Yes | Yes |
Abnormal heart rate alerts | Yes | Yes |
Body battery score | Yes | Yes |
Stress monitoring | Yes | Yes |
Sleep tracking | Yes | Yes |
GPS | GPS, GLONASS, Galileo | GPS, GLONASS, Galileo |
Multi-band GPS | No | No |
SatIQ technology for GPS | No | Accelerometer |
Health Dashboard | Yes | Yes |
Barometric altimeter | No | No |
Gyroscope | No | No |
Sunrise, sunset time | Yes | No |
Control smartphone music | Yes | Yes |
Health dashboard | No | No |
Pedometer | Yes | Yes |
LiveTrack safety feature | Yes | Yes |
Temperature tracking | No | No |
Live Event sharing | Yes (on Android devices) | Yes (on Android devices) |
Charger | Yes, wired charger | Yes, wired charger |
HR broadcast | Yes | Yes |
Calories burned | Yes | Yes |
Weather | Yes | Yes |
Final verdict
Forerunner 55 is costlier than Forerunner 45 by $60. For the price difference, you will get:
- Additional battery backup
- Respiration rate tracking
- Women’s Health
Almost all other features and product capabilities are identical between the Forerunner 55 and Forerunner 45.
Forerunner 45 is a relatively dated product as it was released in 2019. So, it may be worth going for a Forerunner 55 to ensure that we have a relatively newer basic Forerunner smartwatch.
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