Garmin devices tend to last a long time. Not only does the device itself tend to last for a number of years, but often Garmin has these devices on sale and supported for many years. At the entry point to Garmin's Forerunner series - that's devices aimed principally at running, but supporting a wider range of sports - the Forerunner 55 is the latest model. It updates the Forerunner 45 which replaced the Forerunner 35, which in turn replaced the 30. You can see the pattern. But how do these devices differ? If you're a Forerunner 35 user, is it time to consider an upgrade? If you're looking at a great Forerunner 35 deal, should you pay more for the 45 or 55?

  • garminforerunner55square
    Garmin Forerunner 55
    Our top pick

    We love this reasonably-priced Garmin option, which is an ideal entryway for those looking to track their exercise and recovery.

  • garminforerunner45square
    Garmin Forerunner 45
    A cheaper alternative
    $179.99 $199.99 Save $20

    This Forerunner 45 sticks to the basics, but if you're looking for a simple and easy-to-use running watch, plus some added smartwatch features, this watch fits the bill.

  • garminforeunner55square
    Garmin Forerunner 35
    Out of date

    The Forerunner 35 is good value for money, but the design is dated, there are fewer functions and it's not as capable as the newer models.

Design

The big difference in these watches starts with the design. The Forerunner 35 has a rectangular design with a square display. It's also quite thick at 13.4mm and only comes in one size, fitting wrists from 140-200mm. The Forerunner 45 is a lot more modern, moving to a rounded design and coming in two sizes, with the 45S for smaller wrists. The Forerunner 45 is designed to fit 129-197mm wrists, while the 45S will fit 124-185mm wrists, but it's most likely to be about preference and how big or small you want your watch to look.

The Forerunner 55 has very much the same design as the Forerunner 45, designed to fit wrist sizes from 129-203mm. All these models offer 5ATM waterproofing. The Forerunner 35 does look a little more unique and has a fairly small footprint, but we think the Forerunner 45 and 55 just look better and more modern.


  • Garmin Forerunner 55Garmin Forerunner 45Garmin Forerunner 35
    Battery Life14 days, 20 hours of GPS workouts7 days, 13 hours of GPS workouts9 days, 13 hours of GPS workouts
    DisplayColour, 1.04in/26.3mm, 208 x 208 pixelsColour, 1.04in/26.3mm, 208 x 208 pixelsMono, 23.5 x 23.5mm, 128 x 128 pixels

Display

The thing that's likely to have the biggest impact in moving from the Garmin Forerunner 35 to the Garmin Forerunner 45 or 55 is that the newer models have a colour display. That means that everything looks better - there's added pop when you see the colour icons against the dark background, and it's round, so much more conventional in a watch sense. It also has a higher resolution, so is able to reproduce much finer detail.

The Forerunner 35 uses a mono display, so it is black and white and not able to visually give you as much. It has perfectly high contrast, so you can see the information, it just can't use colour for glanceable emphasis. Of course - there are plenty of good applications for mono and if you're just after your running stats then mono will work just fine too, but we really think it's a bit dated now.

Garmin Forerunner 55 review photo 14

Features and functions

The feature list of any Garmin watch is extensive, to say the least. It's also not as simple as what the watch will do, because in some cases it's the analysis of gathered data that you then view in Garmin Connect that makes the real difference. At their core, these watches rely on the same sensors - GPS, heart rate and accelerometer - to drive their functions. Both will offer sports tracking with a bias towards running and collect that data to give you your stats. If you're after only basic stats, then you could well be happy with the Forerunner 35.

But the Forerunner 45 and 55 are much newer technology and offer far wider support for functions beyond the very basics. They support a wider set of satellites, support Garmin Coach and downloadable workouts and go further to give you functions like Body Battery, using that sleep data to better effect. They will also let you customise the watchface with Garmin Connect IQ. The Forerunner 55 offers more than the 45 too: it offers a full range of swimming metrics, while ticking a few other boxes to make the offering a little more advanced than the 45 - but only slightly. If you're a runner, there's little difference, but you get things like recovery time included on the 55, so it's more accomplished.

All round, the feature set on the Forerunner 45 takes a big step beyond the Forerunner 35, while the Forerunner 55 is a smaller step forward over the 45. Additionally, the 35 will only remember the last 7 workouts, whereas the 45 and 55 will give you 200 hours workout memory.

Battery life

The battery life of these devices differs a fair amount. All the additional functionality that the Forerunner 45 offers - as well as that more complex display - means that it gives you 7 days compared to the 35's 9 days. However the Forerunner 55 is a step ahead, offering 14 days of life, so is the best of the bunch. But to achieve that figure you need to not really be using your watch very much. The more you do with it the less life you'll get from it. All these devices offer decent battery life, but the Forerunner 55 is the clear front-runner.

When it comes to actual activity tracking, both the 35 and the 45 - according to Garmin's figures - will give you around 13 hours of tracking. That's going to cover most users' needs, without feeling like you always need to charge your watch. The 55, however, will give you 20 hours of GPS. That's a long day out, for sure.

Garmin's most affordable Forerunner 55 is now even cheaper in Prime Day sales photo 1

Summing up

There's no question which is the best device from this entry-level Garmin selection. Although the Garmin Forerunner 35 has been a great entry point to the world of Garmin fitness trackers for a couple of years, its feature set and design hasn't kept pace with the rest of the lineup. The Forerunner 45 is a great replacement, a fantastic watch for fitness newcomers and more advanced runners, it's every bit worth the extra price you'll be asked to pay for it.

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Garmin Forerunner 55
Our top pick

The Forerunner 55 is more advanced, offering a little more than the 45, but in a package that's very much the same. For those looking for the best price, the Forerunner 45 will probably be the best option, unless you want swim tracking, in which case the Forerunner 55 is the one you want.