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Garmin Forerunner 645 Review

Quick Take

Over the past year, Garmin has released a number of new devices, making it harder than ever to pick just one wearable from the brand. Their latest offerings have the latest and greatest in technology and they feature a much more appealing look compared to some of their earlier devices.

The Garmin Forerunner 645 and 645 Music are the most recent releases and they have the significance of joining the well-loved Forerunner lineup and being the first Garmin wearable with music storage.



Lightweight and easy to use
Awesome running metrics
Good song storage capacity


Weaker battery life
Prone to device error pairing
not a touch screen device

We took an in-depth look at FR 645 to see how it stacks up to the competition and to determine who might love it. Let’s dig in.



Size-wise, the 645 is smaller than the Forerunner 935 and about the same as the Vivoactive 3. It weighs in at 42g, with a physical size of 42.5 x 42.5 x 13.5 mm and a display size of 1.2″ (30.4 mm) in diameter. The screen resolution is 240 x 240 pixels.

The screen makes use of sunlight-visible, transflective memory-in-pixel technology, so it’s easy to read in bright sunlight. The trade-off here is that the screen isn’t as vibrantly colored as some other types of smartwatches, but it’s perfectly clear and easy to read anyway.

Essentially, the 645 resembles all its most recent predecessors in the Forerunner lineup (as well as the Vivoactive 3), so there isn’t much new to report in terms of design. It’s a nice looking watch with a sleek body and attractive screen. You can customize the watch screen and choose which information you want to see when you look at it. The interface is good — it’s easy to navigate and the available information on the watch is useful.


Let’s look at an overview of the key fitness and smart features:

  • Water Resistant: Rated 5 ATM
  • On-Board GPS
  • Garmin Pay: NFC Contactless Payments
  • Smart Notifications
  • Text Response (Android Only)
  • Daily Smart Features: Weather, Calendar, Find My Phone, Find My Watch, and Life Track
  • 24×7 Heart Rate Monitoring: Zones, Alerts, Calories
  • Activity Tracking: Steps, Calories, Distance, Floors, and more
  • Sleep Monitoring
  • Stress Monitoring
  • Preloaded Gym & Outdoor Activity Profiles
  • Preloaded Running, Cycling, and Swimming Profiles
  • Up to 7 Day Battery Life (14 hrs GPS; 5 hrs GPS with Music)
  • Music Storage (On 645 Music Model)

As you can see, it’s fully loaded.

There are smartwatch capabilities, and you can add apps and do fancy things like contactless paying and respond to a text message from your wrist, but it really shines when it comes to the fitness and activity tracking features. Like other Garmin devices, the FR 645 makes great use of Garmin’s excellent tracking and GPS technology. There’s a bit of everything when it comes to sports and activities, so most people (save for hardcore athletes, triathletes, and so forth) should find it to be just right for their tracking needs.


One of the most notable features is the Music functionality available on the FR 645 Music version for about $50 more. This is Garmin’s first offering with built-in music and Bluetooth playback. You can store up to 500 songs on your wrist and go run or do whatever activity you want without needing your phone.

On the down side, it doesn’t work with some of the biggest names in streaming. Only iHeartRadio and Deezer are supported.

Vs. Forerunner 630

Since this is an upgraded version of the Forerunner 630, let’s take a look at the differences. The improvements in the 645 include:

  • Lighter in weight and smaller overall
  • Better screen quality
  • Addition of features like contactless payments, text responding, and music
  • More sensors, including: barometric altimeter, gyroscope, thermometer
  • Swimming profiles

Bottom line? The FR 645 is a huge upgrade from the 645.

Vs. Forerunner 935 & Fenix 5

The FR 645 is pretty similar to the Forerunner 935 and the Fenix 5, with the latter 2 being more expensive and available with some nicer styles (like the Fenix with sapphire glass). The differences are mainly the addition of Garmin Pay, text responses, and music on the 645. The FR 935 and the Fenix 5 also have multisport modes and openwater profiles, as well as advanced navigation and better durability. They also have a better battery life, even without the music.

Who Should Buy the Forerunner 645?

Those who are after the 645 Music are probably most excited about the music. Even outside of the music addition, the FR 645 is a pretty exciting watch from Garmin. It has many of the best features found on premium watches like the FR 935 and Fenix 5, but it costs less. You can even save $5o by choosing the non-music model if that’s not something you’ll use.

For some athletes, triathletes, runners, and marathoners, the multisport modes, open water tracking, and durable design of the more expensive watches are worth the extra money. But for nearly everyone else, the 645 offers basically everything you can need from a smart running watch.


Some early reviews found the 645 to be buggy, but it seems like many of those kinks have been worked out, and the reviews are mainly positive from customers. There are some drawbacks — like the lack of integration with streaming services like Spotify and Pandora, as well as mediocre battery life — but overall it’s an intelligently designed watch with plenty of features. If you are considering making an upgrade from a FR 630 or 235, you’ll see a huge difference. If you’re brand new to Garmin, you’ll likely be pleased by all Garmin watches offer, the solid app, and the wearable design of the Forerunner 645.


Frequently Asked Questions

Q: Does the Garmin 645 Forerunner work with the Spotify App?
A: Spotify is meant to integrate seamlessly with this Garmin running smartwatch, which makes it one of the most robust smartwatches we've ever used for training
Q: Is the Garmin 645 Forerunner music worth it?
A: Yes, there's no question the music helps improve the exercise experience.
Q: Does the Garmin 645 Forerunner have maps?
A: Yes, maps can be downloaded. Hold the watch face up: select Settings under Activities & App, select the activity to customize, select the activity, select Data Screens and Add Map.
Q: How do I follow a course on the Garmin 645 Forerunner?
A: Under Settings and Activities, select Courses and Creat New.
Q: Is the Garmin 645 Forerunner a touchscreen?
A: No, the device is controlled by buttons.
Q: Does the Garmin 645 Forerunner have UltraTrac?
A: Yes, UltraTrac can be used in conjunct with GPS.

See Best Price

Rating: 79%


Product Type


Brand/Model Series

Garmin Forerunner 645

Overall Rating

79 %

Operating System


Phone Control


Number of Available Colors


Type Of Display

MIP - sunlight-visible, transflective memory-in-pixel

Screen Size

1.3 Inch

Screen Resolution




Sleep Tracking


Steps Tracking


Calories Tracking


Downloadable Apps


Bluetooth Enabled


Heart Rate Monitor


Water Resistance Rating

5 ATM - Swimming

Battery Type

Lithium-Ion Battery

What is included in the box?

Charging Cord



On-board music storage


NFC Touchless Payment


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