Within the company's full stable of GPS watches, the Forerunner 645 sits just above the Forerunner 245 in terms of price, though many of the latest features are present in the latter. As such, it can be a little hard to figure out which of these devices is actually better, and which represents the best value for your money.
Below, we'll be breaking down all the key differences between the two and giving you an overview of what you can expect from each.
Garmin Forerunner 245 Music v Forerunner 645 Music: Design
There are plenty of reasons why these two running watches are tough to separate, but the most immediate is the look of each; these are two devices that are remarkably similar in size, screen specs and weight.
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The older Forerunner 645, shown above, clocks in at 42.3mm x 42.3mm x 13.5mm, and the 245 is essentially the same, coming in at 42.5mm x 42.5mm x 12 mm. It's a bit thinner, but that's to be expected with a slightly newer device, and both have the same 1.2-inch, 240 x 240 pixel resolution display and weigh roughly 40g each. If you don't want an all plastic look, the 645 Music is the one to go for. It has that more eye-catching metallic bezel.
Both also have identical room for memory, with 200 hours worth of workouts able to be saved onto the device, and a 5ATM water rating (meaning you can use them for swimming workouts).
Looking for a difference in battery life? Well, again, there's not much on the face of it. Both offer around a week of life in Smartwatch Mode, with that shrinking down to six hours when using continuous GPS tracking and music on the 245, and five hours for the 645. If you're using GPS without any music, expect around 24 hours from the 245 and 14 hours from the 645.
The 245 does though offer an UltraTrac mode commonly found in Garmin's more expensive watches. Using this mode will push battery life in GPS mode, but reduce the data sampling rate leading to less accurate sports tracking.
Of course, it's also important to keep in mind that both editions of these running watches have non-music equivalents available. They're slightly cheaper, too, which we'll detail further below.
Garmin Forerunner 245 Music v Forerunner 645 Music: Features
Naturally, both of these watches are designed to keep tabs on running activity first and foremost, but there's plenty of other activity and sports tracking packed inside, too. We've detailed the performance from both watches in these areas through our extended reviews, but it's also important to keep in mind that they do offer a slightly different package of features.
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Let's look at what you get in both, and then what's exclusive to each watch in order to give you the clearest idea of the differences.
Features in both watches
- GPS, GLONASS and GALILEO sensors
- Wrist-based heart rate monitoring
- 24-7 activity tracking for steps, calories and sleep
- Music storage and streaming for Spotify and Deezer
- Compatibility with iOS and Android smartphones for smart notifications
- Bluetooth, ANT+ and Wi-Fi support
- Tracking modes for running, treadmill running, indoor track running, trail running, yoga, stair stepping, elliptical training, cardio training, cycling, indoor cycling, strength training and pool swimming
Exclusive to the Garmin Forerunner 645 Music
The Forerunner 645 is the only option for those who want Running Power data, as Garmin will only calculate this with watches that have barometric altimeters. However, you'll still need to pair one of Garmin's chest straps or the Running Pod in order to gain these insights.
More exercise tracking modes
With the 645 Music, you'll be privy to a few more exercise modes than on the 245, with five more available. The addition of skiing, snowboarding, XC skiing, stand up paddleboarding and rowing tracking take the 645's tracking modes to a total of 18.
Both of these watches are fairly equal when it comes to smartwatch features, but the 645 Music does have one key advantage: Garmin Pay. This allows users to add their card to the watch and use it to make contactless payments. Throw your wallet away.
Exclusive to the Garmin Forerunner 245 Music
One of the newer features appearing on Garmin watches is the company's Pulse Oximeter, which is used to measure the body's blood oxygen saturation level. Combined with the rest of the heart data being tracked, Garmin is able to more accurately deliver recovery, health and sleep data.
Body Battery Score
Garmin Forerunner 245 Music vs Forerunner 645 Music: Price
As we mentioned up top, the Forerunner 245 sits below the Forerunner 645 in the wider collection of Garmin GPS watches. However, the price does vary depending which version of each device you're interested in β as, again, both come in a non-music variant, too.
The 245 Music costs $349.99, with that dropping to $299.99 if you opt for the watch without music storage capabilities. In comparison, the 645 Music will set you back $449.99, and you can save a little by opting for the $399.99 standard edition.
Garmin Forerunner 245 Music or Forerunner 645 Music: Which is best?
Though both of these running watches are similar in design, they do offer some subtle differences in the feature sets β as well as the price gap β that will likely leave you leaning one way or the other.
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If your priority is a strict budget, you can't go wrong with the Forerunner 245 Music. You get most of the same great tracking features as the 645 range for a cheaper outlay, and a thinner design and better battery life.
That's not to say it's for everyone, though. The Forerunner 645 range, though a little longer in the tooth, still stacks up against the new Garmin devices for 2019.
The battery life is slightly weaker, and it does cost a tad more, but those who want a watch that can help provide Running Power data, accurate data on vertical oscillation and more niche tracking modes β as well as the ever-handy Garmin Pay β should opt for the 645 instead.