Hands-on Gear Review

Garmin Forerunner 645 Music Review

Price:  $450 List | $449.99 at Backcountry
Compare prices at 4 resellers
Pros:  Compact and lightweight, accurate, extensive features
Cons:  Clunky music upload, short battery life with music, expensive
Bottom line:  If you want a lightweight, feature-packed watch that lets you leave your phone at home, go for the Forerunner 645 Music.
Editors' Rating:   
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Main body size:  42.5 diameter, 13.5 mm thickness
Weight, Verified:  43g
Inaccuracy percentage. Variation from actual.:  0%
Manufacturer:   Garmin

Our Verdict

New to the field in 2018, the Garmin Forerunner 645 Music is a compact, feature-filled GPS smartwatch that can store up to 500 music files locally. Users can bliss out to music on the run and leave their phones behind. We definitely enjoyed this function, but the process for uploading music is very clunky and needs improvement. Aside from that, the 645 Music is simple to use, and we were impressed by its deep well of features and its decent battery life given its small size.

Those looking for even more battery power and more advanced navigation features should check out our Editor's Choice Award winner, the Garmin Forerunner 935.



RELATED REVIEW: Best GPS Watches of 2018 for Running & Training


Our Analysis and Test Results

Review by:
Joanna Trieger
Review Editor

Last Updated:
Thursday
June 7, 2018

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Music in your ears without a bulky phone in your pocket — sounds great, right? That's what Garmin promises with its new Forerunner 645 Music, and it delivers, for the most part. While we weren't blown away by this model's music function, it gets the job done, and the rest of the watch's features are rock-solid.

Performance Comparison



Easy to use  the 645 Music lets you get out on the trails in a hurry.
Easy to use, the 645 Music lets you get out on the trails in a hurry.

Ease of Use


Like all the Garmin devices in our test group, we found the Forerunner 645 Music to be intuitive and easy to use. Its five buttons make it easy to navigate through the features, activities, and menu screens, and the data that can be accessed and displayed on the watch itself is customizable.

Navigating through the Forerunner 645 Music's data screens is easy and intuitive. Here  our tester checks out his heart rate after a trail run.
Navigating through the Forerunner 645 Music's data screens is easy and intuitive. Here, our tester checks out his heart rate after a trail run.

Syncing the device with a smartphone was simple, and once connected, our activities uploaded to the Garmin Connect app automatically. Garmin Connect is also easy to use, allowing users to view their daily activities and their progress over time with a series of intuitive widgets.

Garmin Connect is intuitive and easy to use. Shown here is a sample activity displayed in the full web version of the app. The data you see on this screen is customizable  and you can dive deeper into each metric.
Garmin Connect is intuitive and easy to use. Shown here is a sample activity displayed in the full web version of the app. The data you see on this screen is customizable, and you can dive deeper into each metric.

We were slightly less impressed with the ease of uploading music to the Forerunner 645. For files stored locally on your computer (MP3s, etc.), uploading is reasonably simple, if a bit clunky. It requires connecting the watch to your computer via the charger cable and using the Garmin Express desktop app to navigate to your audio files. From there, the upload is a speedy process.

To upload via a streaming service — well, first, prepare to be disappointed. Most popular music streaming services, including Pandora, Spotify, and Apply Music, don't sync with this watch yet. You can upload playlists from iHeartRadio, but you'll have to pay a $9.99/month All Access subscription fee for the privilege. As non-iHeartRadio users, we weren't super stoked at having to switch streaming services for the sake of the watch. You can upload playlists created on iHeartRadio to the Forerunner 645 Music over WiFi, but the watch demands that you plug it into a charger while uploading. All in all, the process works, but it feels old-fashioned and labor-intensive compared to the seamless user experience elsewhere in the watch.

Once we had some content uploaded, listening to music during activities was a breeze. You can access music controls from any screen by holding the "Down" button, and it was easy to navigate between playlists and songs while running and riding. Before testing this watch, we read lots of complaints about unexpected mid-workout reboots, music refusing to sync, and music cutting out during workouts. We did find that we could get the music to cut out if we put our watch wrist all the way under the bike seat while out for a ride, but…why would you do that? Otherwise, we didn't have any issues.

Features


Given its relatively small size, the Forerunner 645 Music has an impressive list of features. Most obviously, this is the only watch in our test group that can store music. This watch also has Garmin Pay, so you can link a credit card to your watch and use it to make purchases in most establishments that accept contactless payments. Beyond that, you'll enjoy most of the GPS, fitness tracking, and smartwatch features available in the burlier Garmin Forerunner 935, with a few variations:
  • The altimeter and barometer functions in the 645 Music can't be calibrated.
  • The navigation tools aren't as sophisticated.
  • Certain advanced running analytics that you can capture when you pair the 935 with the Running Dynamics Pod aren't available with the 645 Music.

We know we ran precisely half a mile. The Forerunner 645 Music agrees.
We know we ran precisely half a mile. The Forerunner 645 Music agrees.

Accuracy


We took the 645 Music out for two sets of two laps on a standard 1/4-mile outdoor track and got perfect 0.50-mile readings both times. All the watches we tested in 2018 were either dead accurate or were just 0.01 miles (2%) off during this test, while the 2017 test group had much wider variations.

We analyzed our GPS tracks after each activity with the 645 Music, and generally, the tracks were accurate based on our known routes. While running, the paces displayed on the watch face lined up with our expectations based on years of running experience.

Even on a cloudy day  the Forerunner 645 Music accurately captured our track along with winding course.
Even on a cloudy day, the Forerunner 645 Music accurately captured our track along with winding course.

Ease of Set-up


Like all the Garmin devices we tested (and most of the other devices, as well), the 645 Music is simple to set up. It's as easy as downloading the Garmin Connect app to your phone, turning on the watch, and following the instructions on the two screens. Set-up took about five minutes from start to finish, and we didn't even need to charge the watch before using.

LOL. We wish this were accurate  but it isn't  especially for the longer distances. Your Garmin will need to collect a few weeks' worth of data before it can accurately predict your race times.
LOL. We wish this were accurate, but it isn't, especially for the longer distances. Your Garmin will need to collect a few weeks' worth of data before it can accurately predict your race times.

Like the other high-end Garmins in our test group, the Forerunner 935 and the Fenix 5, some of the 645 Music's features require a period of use before they become fully functional. Though the watch provides training status information after about a week of use, some aspects — like the race predictor, pictured below — needed more time to improve accuracy.

Without playing music or using GPS tracking  the Forerunner 645 Music will stay charged during a multi-day backpacking trip.
Without playing music or using GPS tracking, the Forerunner 645 Music will stay charged during a multi-day backpacking trip.

Battery Life


For normal day-to-day use (wearing the device 24/7 and tracking 1-2 hours of GPS activities per day), the Forerunner 645 Music needed charging every three to four days without music. Adding music during activities drained the battery quickly, so we had to charge the device every one to two nights.

When we tracked a continuous GPS activity until the battery died (again, without music), the 645 lasted 13 hours, which impressed us given its size. By contrast, the larger Forerunner 935 lasted over 21 hours. If you're an ultrarunner, you'll likely outrun the 645 Music's battery, and even regular marathoners may kill the battery if they listen to music throughout their race. But for those who just want tunes during their shorter training runs, the Forerunner 645 Music's battery life is sufficient.

While the Garmin Forerunner 645 Music (right) is significantly smaller than the Forerunner 935 (left)  the display is a similar size.
While the Garmin Forerunner 645 Music (right) is significantly smaller than the Forerunner 935 (left), the display is a similar size.

Portability


Weighing in at just over 42 g, this watch is among the lightest in our test group. The only lighter watches — the Garmin Vivoactive and the Garmin Forerunner 35 — are more basic models. The 645 Music is pleasantly compact, with a smaller face and a slightly slimmer profile than its cousin, the Forerunner 935. Note, though, that the display on these two models is the same size, so you won't have to squint to enjoy the 645 Music.

The 645 Music lies flat when it's not on your wrist, and its band has quick-release pins so you can remove it easily if you want to slip the watch face into a tight pocket.

Best Applications


Given its relatively low battery life when using GPS and music simultaneously, this watch is ideal for the middle-distance runner who doesn't spend more than a couple hours at a time training. It's also fantastic for day-to-day, around-town use.

Value


Taking into account the other options on the market, we think $450 MSRP is steep for this watch. For just $50 more, you can enjoy much better battery life and improved navigation capabilities in our Editor's Choice, the Garmin Forerunner 935.

If you're set on a Forerunner 645, is it worth it to spring for the music version? Overall, we're not sure this feature is developed enough to justify the extra $50 (vs. the regular $645) plus the $9.99/month you'll have to pay for iHeartRadio if you don't already have MP3s. Knowing Garmin, we'd be surprised if the music feature didn't improve drastically in future versions of this watch. So if you're dying to leave your phone at home today, get the music version. If you can wait, you might benefit.

Conclusion


Even without its innovative music capabilities, the Forerunner 645 Music is a great GPS watch. It has a wide range of features and a pleasantly slim design, and its battery life is solid if you plan your music and GPS use strategically. The introduction of music into this model feels a little premature, so you might be happier waiting a year or two for this technology to improve. But if you do spring for this watch, we bet you'll like it.

Other Versions and Accessories


This watch comes in a non-music version, the Garmin Forerunner 645, which retails for $50 less than the version reviewed here.

Joanna Trieger

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Most recent review: June 7, 2018
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