Garmin Forerunner 55 vs Garmin Forerunner 255: Which running watch should you buy?

a photo of the Garmin Forerunner 55 vs the Garmin Forerunner 255
(Image credit: Future/Tom's Guide)

So you’re thinking of buying one of the best Garmin watches, and you’re trying to choose between the Garmin Forerunner 55 and the Garmin Forerunner 255. Both are excellent watches from Garmin at the more affordable end of the market, but there are some key differences to consider between the two watches. 

For example, the newer Forerunner 255 has a sensor to record blood, breathing rate stress and more. And you can get your favorite tunes on the 255 if you spring for the Forerunner 255 Music. If you’re ready to dive straight into our longer reviews, check out the Garmin Forerunner 55 review here, and our Garmin Forerunner 255 review

While some of the watches in the Garmin range will have extras like Solar charging and touchscreens, if you’re just looking for a running watch that’ll help you keep on top of your training, show you your stats on your run and have the option to track a swim or your cycle commute, you probably don’t need to spend upwards of $300. 

Here's how the Garmin Forerunner 55 vs. Garmin Forerunner 255 comparison stacks up. 

Garmin Forerunner 55 vs Garmin Forerunner 255: Price and availability

The Garmin Forerunner 55 is Garmin’s entry-level running watch, released in June 2021. It costs $199/£179, but you’ll often find it a lot cheaper right now, as the watch has been out for over a year. Its silicone band comes in three different colors: black, white, or aqua. You can only get the Forerunner 55 in one size — 42mm.

The Garmin Forerunner 255 is the newer watch, released in June 2022. It comes in two different sizes — a 42mm (the Forerunner 255S) and a 46mm, and both cost the same. The Forerunner 255 also comes with the option to store music, or not — without music, the watch costs $349/£299, and the Forerunner 255 Music costs $399/£349. 

Winner: Garmin Forerunner 55 — as the older watch, you can pick up the Forerunner 55 at a discount. If you’re on a budget, the Forerunner 55 is a fantastic, affordable running watch. 

Garmin Forerunner 55 vs Garmin Forerunner 255: At a glance 

Swipe to scroll horizontally
Header Cell - Column 0 Garmin Forerunner 55Garmin Forerunner 255
Display size26.3mm27.5mm (255S), 33mm (255)
Battery life (smartwatch mode)2 weeks12 days (255S), 14 days (255)
Battery life (GPS mode)20 hours20 hours without music/ 5.5 hours with music (255S), 25 hours without music/ 6.5 hours with musch (255)
Built-in GPSYesYes
Heart rateNoYes
Garmin PayNoYes
Pulse OxNoYes
MusicNoYes (on Forerunner 255 Music)
Advanced performance metricsNoYes

Garmin Forerunner 55 vs Garmin Forerunner 255: Design and display 

Both the Forerunner 55 and the Forerunner 255 look pretty similar in design, especially if you’re comparing the Forerunner 255S — they both have round, 42mm displays, with five buttons to navigate around the watch, three on the left and two on the right. 

a photo of the heart rate chart on Garmin Forerunner 255

(Image credit: Future/Jane McGuire)

As the newer of the two watches, the screen is slightly brighter on the Forerunner 255 — the larger 255 has a display resolution of 260 x 260 pixels, and the 255S has a display resolution of 218 x 218 pixels, making both brighter than the Forerunner 55’s 208 x 208 screen. That said, all three watches are bright and easy to see, even in direct sunlight. It’s not a difference you’d really notice unless staring at the two watches side-by-side (welcome to my world), but the screen on the newer watch definitely looks a little brighter and more colorful. 

They also both look nice on the wrist — during testing we found neither watch looked overly large on the wrist, and both are available in a few different colors. They also both come with a silicone sports strap, but are both compatible with Garmin’s quick release bands, so you can swap the strap for a metal or leather strap should you wish. 

Winner: Garmin Forerunner 255 — this is a tough one to call, as both watches look and feel very similar on the wrist, but the brighter screen and the option to choose between two different sizes gives the Forerunner 255 the edge.

Garmin Forerunner 55 vs Garmin Forerunner 255: Battery life 

Compared to the likes of the Apple Watch Series 8, both the Forerunner 55 and Forerunner 255 have impressive batteries, and with both watches you can easily go a few days without needing to charge. The Forerunner 55 has a slightly better battery life than the smaller Forerunner 255 in smartwatch mode — 2 weeks, compared to 12 days, although this is down to the higher resolution screen on the newer watch. The larger Forerunner 255, however, also lasts for 14 days. 

In GPS mode, however, the Forerunner 255 can last up to 25 hours, whereas the smaller Forerunner 255S and the Forerunner 55 can last up to 20. It is worth noting, however, that if you’re listening to music on the Forerunner 255 this number dwindles dramatically to just six and a half hours. 

Garmin Forerunner 55 review

(Image credit: Tom's Guide)

Winner: Garmin Forerunner 55 — looking at the three watches side by side, there’s really not a lot in it, and for about $100 less, if you’re not bothered about listening to music from your watch, the Forerunner 55 is a great pick. 

Garmin Forerunner 55 vs Garmin Forerunner 255: Fitness tracking and features 

Here’s where things get a little different. Both watches can track indoor and outdoor runs, indoor and outdoor bike rides, swimming, cardio, elliptical sessions, and yoga. They’ll both also track your daily steps, heart rate, stress, sleep, and menstrual tracking. They also both use the same Garmin Connect app, which is a valuable tool and helps make it easy to see all of your health data in simple graphs and graphics. 

Garmin Forerunner 55 review

(Image credit: Tom's Guide)

Both watches are able to tell you things like your VO2 max, your recommended recovery time after a run, and your body battery — a useful tool that looks at your activity levels, heart rate variability, and stress levels to help you see at a glance how prepared you are for a difficult workout. Both also have the PacePro feature, which stops you from starting a race too fast, and suggested workouts, as well as the LiveTrack and Incident Detection safety features. Plus, you can use the Garmin Connect app to download training plans onto both watches. 

a photo of the heart rate chart on Garmin Forerunner 255

(Image credit: Future/Jane McGuire)

The Forerunner 255, however, has inherited some of the more advanced health features usually reserved for Garmin’s more expensive running watches. The watch has Garmin’s latest Elevate V4 sensor — the green light records heart rate, the red light records blood oxygen levels (referred to as Pulse Ox on the watch). This sensor is used to calculate breathing rate, HRV, and stress. 

The Garmin Forerunner 255 also has Garmin’s newer features like the Morning Report, which gives you a snapshot into how well you slept, how hard you’ve been training, and a look at the weather for the day ahead. The Forerunner 255 also includes Garmin’s Health Snapshot feature, as well as Garmin’s Acute Load and Up Ahead features. You can also now access triathlon and multisport activity profiles on the watch.

Winner: Garmin Forerunner 255 — in our review, we were blown away by the amount of advanced features available on this mid-range watch. While the Forerunner 55 has always been considered the lighter version of the 255 range, if you’re looking for advanced training metrics, the 255 is the watch to pick. 

Garmin Forerunner 55 vs Garmin Forerunner 255: Smartwatch features 

Both watches have all the basic smartwatch features we’ve come to expect from our wearables, including weather, the ability to read messages on the move, calendar reminders, and things like find my phone and find my watch. 

a photo of the Garmin Forerunner 255 home screen

(Image credit: Future/Jane McGuire)

From a smartwatch perspective, the main difference between the two watches is that, if you buy the Forerunner 255 music edition, you have the option to upload music to the watch, or listen from Spotify, Deezer, or Amazon Music, and leave your phone at home. 

The newer watch also has the option to use Garmin Pay, allowing you to pay for transactions from your wrist. 

Winner: Garmin Forerunner 255 — there’s not much in it if you don’t go for the music version of the Forerunner 255, but if you do, the option to store music on your watch and listen without your phone is great.

Garmin Forerunner 55 vs Garmin Forerunner 255: Which should you buy? 

When it comes to which watch to buy, the best running watch for you is the one that has the features you need to reach your goals. If you’re a beginner, the Forerunner 55 has everything you’d need and more. We’d also argue that even if you’re a more experienced runner on a budget, you’ll probably find all you need on the Forerunner 55. 

On the other hand, if you’re a more experienced runner, you want more advanced training metrics, or the option to train for a triathlon, the Garmin Forerunner 255 is the obvious choice. It’s an excellent watch, that also has the option to store music and leave your phone at home when you run. 

Either way, both watches are a brilliant investment and will make it easier to track your training. 

If you’re looking to save even more money, the Forerunner 255 replaced the Forerunner 245 earlier this year. Check out our Forerunner 245 vs Forerunner 255 face-off to see the main differences between the two watches, as well as our Forerunner 55 vs Forerunner 245 face-off

Jane McGuire
Fitness editor

Jane McGuire is Tom's Guide's Fitness editor, which means she looks after everything fitness related - from running gear to yoga mats. An avid runner, Jane has tested and reviewed fitness products for the past five years, so knows what to look for when finding a good running watch or a pair of shorts with pockets big enough for your smartphone. When she's not pounding the pavements, you'll find Jane striding round the Surrey Hills, taking far too many photos of her puppy.