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Garmin Forerunner 645 Music review: Music, Garmin Pay, and comprehensive data capture motivate for success

Written by Matthew Miller on

Garmin Forerunner 645 Music (black)

$189.99 at Amazon
  • Lightweight and very comfortable
  • Multi-day battery life
  • Music and payment support without a phone
  • Accurate GPS and activity tracker
  • Clear and crisp color display
  • Easy to use interface
  • Five button navigation with no touchscreen
  • Outstanding software providing all the data you could ever want
  • Music setup is a bit clunky
  • Editors' Review
  • Specs

Over the past few years, I have tested various Garmin GPS sports watches, including the Forerunner 225, Forerunner 935, and Fenix 3 HR. One feature missing from all of these that I find essential for my recreational running, offline music streaming support, has finally come to Garmin in the form of the Garmin Forerunner 645 Music.

I ran with folks from Garmin, iHeartRadio, Firstbeat, and GU at CES with the SkullCandy Method wireless headset connected to a Garmin Forerunner 645 Music and enjoyed that brief time with this GPS sports watch. I've been running and cycling with the 645 Music for that past couple of weeks and think Garmin may have hit the sweet spot with the Forerunner 645 Music.


  • Display: 1.2 inch (30.4mm) 240x240-pixel resolution transflective memory-in-pixel color chemically strengthened glass
  • Storage: About 3.6GB of internal storage for up to 500 songs and 200 hours of activity data
  • Water resistance: 5 ATM
  • Connectivity and sensors: WiFi, Bluetooth 4.0 LE, ANT+, GPS, GLONASS, optical HR, barometer, compass
  • Bands: 20mm industry standard replaceable strap
  • Battery: 300mAh rechargeable lithium-ion. Five hours in GPS training mode with constant streaming music and up to 7 days in smartwatch mode with 24/7 HR monitoring
  • Dimensions: 42.5 x 42.5 x 13.5mm and 42.2g.

The Garmin Fenix 3 HR has been my personal GPS sports watch since 2016 and the most obvious difference right out of the box is the weight of the Forerunner 645 Music. It's about half of the Fenix 3 HR. It weighs in at just about the same as the Fitbit Ionic.


The Garmin Fenix 3 HR was the first Garmin I purchased for myself for long term use, and it has served me very well. If I want to enjoy music though, it has required that I carry a phone or other music player when I run. This isn't a terrible experience because I often capture photos during my runs, but it is also a bit freeing to leave the phone behind and just get out and run.

I also find the sleep tracking on Garmin devices to be useful, but only wore the Fenix 3 HR to bed a few times since it tended to knock my wife out as I twisted and turned in the night. It's really just too large and heavy to sleep with every day.

The Garmin Forerunner 645 Music looks like a typical Garmin device with a round face, stainless steel bezel, solid plastic back, and silicone strap. I love that it has the traditional five-button design with no touchscreen capability. When you run in the rain, sweat a lot, and want to switch screens or interact with your device the ability to control things with buttons is preferred.

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The Garmin Forerunner 645 Music fits my 6-foot-1 inch, 250-pound frame well, but it's also likely to fit others since it is only 42.5mm in diameter and quite light. It is about as thick as an Apple Watch and slightly thinner than other Garmin devices I have recently tested. Universal 20mm bands can be used on the 645 Music, which means you can find a number of affordable band options on Amazon. You can dress it up or down to fit your needs.

The soft silicone band that comes with it works fine, and I like the soft feel of it. A notched loop keeps the bitter end in place, but it's also a bit of pain to move to other openings and remove. Then again, it is so comfortable and light that I only took it off to charge it every four or five days. This securing method also ensures the band stays on all the time, even during intense activity. The silicone band has a number of openings to fully adjust to your wrist size. The clasp is metal with a matte finish.

The display is not a touchscreen, so all interactions are carried out through the use of five buttons -- three on the left and two on the right. The display is the same size as most other Garmin watches, but the resolution is higher than most at 240 x 240 pixels. It looks great in all lighting conditions and is very visible even in bright direct sunlight.

The buttons are used for the following, moving from the top right and going clockwise: Start/stop/select, back/lap, down, up, and light. The software associated with these button presses are described in detail in the watch software section of the review.

The optical heart rate monitor is centered on the back of the Garmin Forerunner 645 Music and this time it is nearly flush with the back. It incorporates Garmin's newest elevate optical HR sensor for 24x7 recording every second. I never felt any discomfort caused by the heart rate monitor pressing against my left or right wrist.

There are four charging pins recessed on the side of the back. A proprietary USB charging cable and clamp is included with the Garmin Forerunner 645 Music. I confirmed that the advertised time of five hours for GPS tracking and music playback is accurate during my weeks of testing. I generally run three days a week for about 45 minutes to an hour each time, with music playing, so was able to get about five days between charges with these runs and 24/7 life tracking.

You can also connect the HRM-Run heart rate monitor strap, a $99.99 accessory, or a Running Dynamics Pod ($69.99) for an additional six running dynamics metrics. These include cadence, vertical oscillation, ground contact time, ground contact time balance, stride length, and vertical ratio.

Garmin Forerunner 645 Music review: in pictures

Watch software

If you have used Garmin GPS sports watches before then it will be quick and easy for you to pick up and use the Forerunner 645 Music. Even if you are new to using these five buttons to navigate, it should only take you a short period of pressing the different buttons to figure out how to navigate around and find everything. There is a lot going on here with the Forerunner 645 Music, but the words that appear as you navigate are clear and easy to understand.

The main watch faces that are provided by default are fine, but I went to the Connect IQ store and installed a couple of other watch faces that provide a guick glance at the daily activity tracking that is important to me.

You can use the Garmin Forerunner 645 Music to track running, biking, treadmill, indoor track, indoor biking, pool swimming, snow skiing, snowboarding, cross-country skiing, stand-up paddleboarding, rowing indoors and outdoors, walking, strength, cardio, yoga, elliptical, stair stepper, and others. Golfing and hiking are activities I tracked on the Fenix 3 HR, but they are not options on the Forerunner 645 Music. You can get more applications from the Connect IQ Store, so I installed the 7-minute workout, too, since I like to perform body-weight exercises. In my weeks of testing, I primarily used the running and cycling tracking, as detailed below.

The Forerunner 645 Music also offers the ability to track your phone by sending a signal to it via Bluetooth so that an audible alarm sounds to help you find your connected phone.

While the watch face appears all the time, pressing the up or down button scrolls through your available widgets. By default you can see your steps, performance, weather, notifications, heart rate, last run, music controls, and calendar. You can reorder these and also download more widgets on the Connect IQ store.

Like most recent Garmin devices, the 645 Music has an integrated Wi-Fi radio so you can have your activity data synced to your Garmin Connect account when you return to a Wi-Fi zone previously established. It's great to enter my house after working out and have my data synced automatically to my Garmin account.

Press and hold on the light button to access a number of options, including find my phone, timer, stopwatch, wallet, lock keys, do not disturb toggle, sync, connection status, and power down. Garmin has a nice new interface where the options appear with color icons in a circular layout that you rotate using the up and down buttons. This looks to be a perfect interface for a Samsung Gear rotating dial and maybe that is something we will see in the future from Garmin.

Pressing and holding in on the up button provides access to watch face options, alarm clock, history, and the vast number of other settings.

Pressing and holding in on the down button brings up an entirely new interface we haven't seen before. This action takes you to the music interface that looks similar to the light button press and hold with various options in a circular format that are accessed by moving up or down. Press the top right button, also highlighted in this interface, to make your selection. Options in the music interface include manage providers and headphones, choose your source as the 645 Music or your connected phone, volume controls, play/pause, skip ahead, move back, repeat toggle, and shuffle toggle.

There are an incredible number of settings and customization options available that I cannot begin to cover them all here in this review. For example, in the running app you can customize what may be an unlimited number of data screens (after setting up eight I ran out of data to add) in a layout from one to four fields with timer, distance, pace, speed, heart rate, dynamics, cadence, temperature, elevation, compass, navigation, muscle oxygen, and other fields. I recommend you spend some quality time customizing everything exactly how you want it and then be ready to tweak things as you perform your activity and find you want to view your data differently. I prefer to run with three screens and have my primary one show four fields for quick glanceable info.

You can setup alerts, train to a metronome, select auto laps and auto pause, view 3D speed or distance, have your data fields auto scroll, and even change up all of the colors. It's actually rather stunning how much customization is available on the Forerunner 645 Music, which means it will satisfy every user's needs.

One feature I did not notice on the Forerunner 935, but found quickly on the Forerunner 645 Music is the performance measurements provided by Firstbeat. It is one of the selected widgets from the main interface and requires a few workouts before providing you with some insights. You can see your training status, VO2 max, recovery time, training load, and race predictor. I am currently training for another half marathon with a goal to achieve a personal best. My best half was my first one with a time of 1 hour and 57 minutes, so I am shooting for 1 hour and 45 minutes. Currently, the performance measurements estimate a time of 1 hour and 56 minutes, so I am on the right path to improve this time.

If you wear the Forerunner 645 Music at night, it will track your sleep automatically. Sleep data is captured and presented as deep or light sleep with awake times. It is not quite as thorough and useful as the Fitbit sleep tracker, but it's still helpful. I tend to take naps on the weekends if I get up very early to watch English Premier League football, but it doesn't seem to track short periods of sleep like this and I did not see an option for manually tracking sleep.

Garmin Pay just launched yesterday, and I was able to set it up with my Bank of America Alaska Airlines Visa card. My USAA Visa debit did not work, and I understand that MasterCard support has not yet rolled out. You do have to enter a PIN using the up, down, and select buttons while making a payment and then you can see a status countdown go around the display to show you how much time you have remaining to make the payment.

Smartphone software and website

Collecting the data is important, but using that data for tracking trends, improving performance, challenging friends, and identifying problem areas is also very important. Garmin is one of the few companies that offers the Garmin Connect app for iOS, Android, and Windows 10 Mobile. The app was recently updated and I prefer it over the last version that I also enjoyed using.

When you first launch the smartphone app you will see a screen called My Day. This is a dashboard and completely customizable to your preferences. Simply scroll to the bottom and choose to Edit My Day. Here you can choose from the following cards: Heart rate, steps, intensity minutes, floors, sleep, stress score, weight, and calories. There are also toggles to see yesterday's stats and the last 7 days of stats. In addition, when you record an activity (run, bike ride, etc.) on that day a box appears up top with that card. Tapping any card takes you into much more fine detail for that measurement.

Other tabs in the smartphone software include challenges, calendar, news feed, and notifications. Tap on the tab icon to see more details for each of these.

You can also tap the upper left menu icon to jump to insights, activity stats, health stats, workouts, course, segments, gear, connections, groups, LiveTrack, download golf courses, Connect IQ store, Garmin devices, settings, and help. This menu and user interface matches what you see on the website as well. You can view data over different time frames, see your records, view the badges you earned, see totals and averages, and much more.

There are options to control phone notifications during your activity and at all other times when you are not recording data as part of activity. If you are connected to an Android smartphone, you can go to Settings>Smart Notifications in the Garmin phone app to customize exactly which apps provide notifications to the Forerunner 645 Music. You do not have this per app control when connected to an iPhone. (Thanks to Dave Haas for directing me to this setting.)

With a paired Android phone, you can also select to reply to messages with text you have already setup in advance on your phone. This includes customized text responses.

Once you select the Garmin Forerunner 645 Music in the devices list, you can then access all of the specific settings that will appear on the watch. Through this utility you can organize which apps, widgets, and watch faces appear and in what order. You still need to work directly on the watch to customize data fields and such, but this helps you control the Connect IQ part of the experience.

The Garmin Connect website experience is very similar to what you see in the smartphone application, with even more capability to generate reports, import or export data, setup connections to other applications (such as Strava, RunKeeper, and MyFitnessPal), and more. Similar to the snapshots interface on the phone, you have a dashboard on Garmin Connect that you can customize.

I created dashboard tabs for daily activity, running, cycling, and hiking since those are my primary activities. You can then customize the view that appears in your dashboard or choose to jump to a full page view of the selected data.

Over on the left you will find the three line button that opens up a massive list of options you can navigate to for more data and information. Another option lets you manage your profile, settings, and 3rd party connections.

Computer software

One way to manage your device is through desktop software called Garmin Express. While updates to the watch can come through your smartphone, I find connecting to a computer a more reliable way to check and insure I have the latest firmware on the watch.

I rarely ever look at Quick Start Manuals, but I highly recommend you look through this one and find it interesting that the manual in the evaluation unit had a red Post-It flag for the music section since this is a new feature and getting music onto your Forerunner 645 Music is on aspect that is not intuitive.

The Garmin Express utility for the Forerunner 645 Music includes areas for music, IQ apps, tools & content, and Garmin Connect. Garmin Connect is the website where you view your data and create reports.

The new unique feature for this watch is obviously music. Selecting the music option takes you to a screen showing My Music and Music Apps. Music on your computer can be organized by playlists, artists, albums, songs, genres, podcasts, and audiobooks. You select the folders on your computer where you want to scan for such content. It's not the most elegant solution, but it gets the job done.

After finding content on your computer, you select that content and choose to transfer it to the Forerunner 645 Music. You can browse your computer and watch music content within this utility.

There are currently no music apps listed in the Connect IQ store so stay tuned for further developments there.

In the US, Garmin has a partnership with iHeartRadio to provide music content for Forerunner 645 Music owners. You need to pay the monthly subscription fee of $9.99 to get All Access service in order to sync to the Forerunner 645 Music. While I listened to an iHeartRadio station during my introductory run at CES, the service has not yet launched for the Forerunner 645 Music so you need to manually transfer songs you own to the device at this time.

Pricing and competition

You can purchase the Garmin Forerunner 645 Music now for $449.99. If you don't need the music functionality, you can save $50 and purchase the Forerunner 645 for $399.99.

For music playback, the best alternatives are the Fitbit Ionic, Apple Watch Series 3, Samsung Gear S3, and Samsung Gear Sport. These range in price from $300 to $350. TomTom has the Spark 3 Cardio + Music for $249.99, but it has less capability than the Garmin Forerunner 645 and has a mono display.

The current $449.99 price of the Garmin Forerunner 645 Music may be about $50 too high to compete with these options, but that depends on how much vast amounts of data and performance measurements mean to you.

Daily usage experiences and conclusion

The primary focus for this new Forerunner 645 Music is the music so let's talk a bit about my experiences in this area. Garmin has a list of compatible headphones with notes in the right column about the preferred wrist to wear the 645 Music. I tested out the Samsung Gear IconX (2018), Jabra Elite Sport, Blueant Pump HD, and Skullcandy Method Wireless headsets over my time with the watch. The Skullcandy headphones are the only ones listed by Garmin, but the rest worked fine if worn on the wrist that offered the best signal.

First let me caveat this by saying I am 73 inches tall and weigh just over 250 pounds at this time. My chest is about 48 inches around, so I have quite a bit of mass for Bluetooth to pass through. Thus, the Jabra and Samsung headphones were terrible when I wore the 645 Music on my left wrist. It cut out and completely disconnected every time. Wearing the 645 Music on my right wrist solved that issue with these headsets so your experiences may vary. The Blueant and Skullcandy headset performed flawlessly with the 645 Music on either wrist.

While I try to cover my experiences and details of wearables here on ZDNet, no one beats Mr. Ray Maker when it comes to wearable tech reviews. I highly recommend you check out the DC Rainmaker full review of the Garmin Forerunner 645 Music.

Without the music, the Forerunner 645 Music is essentially a Forerunner 935 or Fenix 5 device, in terms of activity and sports functionality. However, it is also less expensive so even if you don't want the music support you can still save over these other devices and have a capable GPS sports watch. There is even a Garmin Forerunner 645 that sells for $50 less, but I prefer to have the capability for music so am looking to this watch as my next wearable purchase.

It is very quick and easy to press in on the top right button, choose run and press it again, and then see the display turn green seconds later as a GPS signal is acquired. I ran in Florida, New York City, and at home in Washington State and the Forerunner 645 performed flawlessly in all of these locations.

I also connected the Forerunner 645 to my Garmin speed and cadence sensors in order to track more details of my cycling. Again, the connection was reliable and the data interesting.

Nothing is ever perfect, but the Garmin Forerunner 645 Music gets as close to perfection as possible with the ability to track multiple sports, play music without a phone, buy things at stores without a phone, track your activity and sleep 24/7 for several days, and serve as a basic smartwatch for essential notifications. It provides much more detail and data than an Apple Watch or Fitbit, so it's a great fit for the casual athlete who wants more than the basics.

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