Garmin Forerunner 645 Music, Slate

Last updated date: March 12, 2021

DWYM Score

8.7

Garmin Forerunner 645 Music, Slate

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We looked at the top Garmin Watches and dug through the reviews from some of the most popular review sites. Through this analysis, we've determined the best Garmin Watch you should buy.

Editor's Note March 12, 2021:
Checkout The Best Garmin Watches for a detailed review of all the top garmin watches.

Overall Take

This is a smartwatch that can store and play back up to 500 songs without a phone, all while dynamically monitoring your heart rate and running technique. The performance features on this watch‚ including contactless pay and an easy-to-use interface, create a unique sense of freedom.


In our analysis of 12 expert reviews, the Garmin Garmin Forerunner 645 Music, Slate placed 4th when we looked at the top 10 products in the category. For the full ranking, see below.

From The Manufacturer

Easily download up to 500 songs to your watch, and connect with Bluetooth headphones (sold separately) for phone free listening. Syncs music from select streaming services for offline listening. Fits wrists with a circumference of 127-204 millimeter. Display size - 1.2 inch (30.4 millimmeter) diameter. Garmin Pay contactless payment solution lets you make convenient payments with your watch, so you can leave your cash and cards at home. Uses wrist based heart rate to offer performance monitoring Features, including evaluating your current training status. Battery life: Up to 7 days in Smartwatch mode; 5 hours in GPS mode with music. Strap material: Silicone. Display resolution: 240 x 240 pixels. Display type :sunlight-visible, transflective memory-in-pixel (MIP).

Expert Reviews

Expert Summarized Score

6.0
1 expert reviews

User Summarized Score

8.9
2,747 user reviews

What experts liked

The Forerunner 645 Music is a watch that can track a huge variety of sports and look good while doing it.
- Tech Radar

What experts didn't like

The headline music playback feature feels a bit half-baked and the battery life isn't as good as we've experienced on other Garmin watches.
- Tech Radar

An Overview On Garmin Watches

Bear in mind how you intend to use your Garmin smartwatch when shopping for one. Is it primarily for tracking your workouts, for hands-free access of your phone’s messages or for monitoring your health? Some watches include the ability to store and play music independent of your phone, while others need to be within Bluetooth range of your phone to do so.

Consider how often you feel comfortable charging your smartwatch, which will vary depending on how you use it. Using the GPS function actively will drain more power than passive tracking. If you want to use more high-powered applications, you will have to charge your watch every day. Having your watch monitor your health and then accessing the data on your phone or computer will allow you to go days between charges.

While all of Garmin’s smartwatches monitor the wearer’s heart rate, stride and location, some will also monitor the oxygen and water saturation of your skin to estimate stress levels. Still others are capable of monitoring details as small as how long your feet are in contact with the ground as opposed to how long you are in the air, in order to suggest more efficient techniques for running. As the precision and breadth of measurements increases, so will the price of the smartwatch; determining where the balance of features to cost lies is up to each shopper.

The Garmin Watch Buying Guide

  • Garmin offers an app available in both the Android and iPhone stores to collect and analyze the data your watch measures. You can use this to keep an eye on trends as well as adjust your watch’s setup.
  • The Garmin app is also accessible on their website, so you can still use this function if you don’t want to download the app.
  • Several of Garmin’s smartwatches and apps will evaluate your running stride, ground contact-to-air time ratio, breathing and stress patterns. These evaluations are then used to suggest ways to fine-tune your workouts.
  • You might consider purchasing replacement bands for your smartwatch if you are going to be particularly active. A broken band will effectively make the watch unusable until replaced, and having spares on hand will prevent losing important exercise data.