Garmin Forerunner 55 vs. 255: Which Should You Pick?

Garmin Forerunner 55 vs 255

Garmin has been upgrading its watch series, making them more and more capable. Previously, its entry-level line didn’t track pool swimming, but now the FR55 does. And before, the Forerunner 200 range didn’t have open water swimmming or a barometric altimeter, but now it does. The FR55 is basically a FR245 lite, while the FR255 is fit for the Forerunner 700 triathlon range.

With all these updates, it can be hard to decide which watch is right for you. In this post, I’ll be breaking down the similarities and differences of these two popular Garmin watches, and how to decide on one over the other. 

As context for my review, I’m a GPS watch nerd who’s tested the most popular Garmins thanks to loaners or my friends. I train mainly for marathons, but have also dabbled in trail running and triathlons. I don’t own the FR55 or FR255, but I bought the FR55 used for my mom, and am testing out a FR255 loaner. I do a lot of GPS watch comparisons, so if you’re deciding between other models, take a look at those (and follow my Strava to see what I’m currently testing)!

This post is not sponsored, but it does contain affiliate links, meaning that I earn a small commission on any purchases, at no extra cost to you. Your support allows me to keep writing reviews like this one 🙂

Things in Common: Forerunner 55 and 255

Forerunner 255S and Forerunner 55 side by side, lying flat
The back side of the Forerunner 255S and Forerunner 55
side view of the Foreunner 255S and FR55

The Forerunner 55 and 255 are pretty different in terms of capability, but they share baseline features. Here’s what they have in common:

Fitness tracking for common activities: running indoors/outdoors, biking indoors/outdoors, pool swimming, cardio, elliptical training, stair stepping, HIIT, pilates, and yoga.

Everyday fitness stats: steps, heart rate, stress, sleep, menstrual tracking.

Training metrics: VO2 max, Recovery Time, Race Predictor, Body Battery (energy levels based on heart rate variability, stress, and activity).

Workout features: interval workouts, PacePro (helps you create and stick to a pacing plan), suggested workouts, and Audio Prompts via the Garmin Connect app.

Basic smartwatch features: weather, calendar, messages, find my phone, find my watch, Smart Lock (automatically unlock your phone when watch is in range).

Safety features: LiveTrack and Incident Detection, allowing loved ones to track you during your workouts and be alerted if an incident is detected (your watch must be connected to your phone to access these features)

Reasons to Pick the Forerunner 55

Forerunnner 55 in aqua on my wrist
the Forerunner 55 lying flat
Forerunner 55 lying flat with the heart rate monitor facing up

Since the FR55 is Garmin’s entry-level watch, it has fewer features, so there won’t be many perks it has over the FR255. That said, it could still be the better watch for you.

The biggest reason to pick the FR55 would be the lower cost. The Forerunner 55 retails for $200, while the Forerunner 255 costs $350-400, depending on whether you want music functionality.

The FR55 also weighs less than the FR255, including the smaller version, the FR255S. The FR55 weighs 37g, while the FR255S is 39g and the FR255 is 49g. If you prefer not to notice your watch as much on your wrist, then you might opt for the FR55 or FR255S.

Keep in mind, however, that the screen size of the Forerunner 55 is smaller at 1.04″ and the resolution is not as good at 208 x 208 pixels (compared to 1.1″ and 218 x 218 pixels for the FR255S and 1.3″ and 260 x 260 pixels for the FR255).

With that, let’s get into the additional features you’d get on the Forerunner 255.

Reasons to Pick the Forerunner 255

Forerunner 255S on my wrist in the direct sunlight
Forerunner 255S music in black lying flat on a white surface
Heart rate sensor of the Forerunner 255S

As mentioned, the Forerunner 255 comes in two sizes: the FR255 and FR255S (pictured in this post). The FR255S was made for people with smaller wrists, so it has a thinner, shorter strap and weighs about 20% less than the FR255 (it also has a thinner, shorter strap than the FR55). The watch case is also smaller at 41mm vs. 46mm.

I have baby wrists and hands and found that the FR255S was a good size for me—the excess strap didn’t hit the other side of the watch case as it usually does, though I still had a decent amount of leeway.

Besides the variety in physical size, the Forerunner 255 also offers a wider range of activity tracking. These are the tracking profiles that aren’t on the Forerunner 55 that are on the 255.

CategoryActivity Profiles
RunningIndoor Track Running, Trail Running, Ultra Running, Virtual Running
BikingMountain Biking, eBiking, Mountain eBiking
TriathlonOpen Water Swimming, Triathlon, Multisport
OutdoorHiking, Stand Up Paddleboarding, Rowing, Archery
WinterSkiing, Snowboarding, XC Classic Skiing, Ice Skating
GymStrength, Indoor Rowing, Boxing, Mixed Martial Arts
RacquetTennis, Padel, Table Tennis, Platform Tennis, Pickleball, Squash, Raquetball, Badminton
TeamBasketball, Volleyball, Field Hockey, Ice Hockey, Football/Soccer, American Football, Lacrosse, Rugby, Ultimate Disc, Cricket, Softball, Baseball

The biggest additions to the Forerunner 255 series are the Open Water Swimming, Triathlon, and Multisport modes. Previously, you had to go up to the Forerunner 700 series for triathlon capabilities, and those watches retailed ~$500. In fact, it’s quite possible that the FR745 will be the last of the series since the FR255 is now a triathlon watch.

There was also a major update in Summer 2023 that added the additional racquet and team sports, along with a couple specialized profiles like Archery, Boxing, and MMA.

While the battery life on the FR55 is already solid at 2 weeks on smartwatch mode and 20 hours on GPS mode, the FR255 lasts even longer.

Smartwatch modeUp to 14 daysUp to 12 days
GPS-Only GNSS modeUp to 30 hoursUp to 26 hours
All-Systems GNSS mode with musicUp to 6.5 hoursUp to 6.5 hours
All-Systems GNSS modeUp to 25 hoursUp to 20 hours
All-Systems GNSS mode plus Multi-BandUp to 16 hoursUp to 13 hours
The FR255 additionally has UltraTrac mode for super long events, but no battery life estimate for that. Keep in mind that this mode also isn’t very accurate and should only be used in a pinch.

Some of these terms may sound like gibberish, so let me explain. “GNSS” stands for Global Navigation Satellite System. “All-Systems” lets the watch use any of the satellite systems (GPS, GLONASS, Galileo, BeiDou, QZSS) and switch between them based on the quality of their signals. “Multi-Band” is the dual-frequency option that allows your watch to get L1 and L5 frequency signals, improving tracking accuracy.

The FR55 doesn’t have All-Systems or Multi-Band (it does have GPS, GLONASS, and Galileo), so these GPS tracking options are another perk of the FR255. Of course, the FR55 is still accurate, so these additional tracking options may only make a difference if you’re training a lot in cities with skyscrapers or remote areas with poor signal.

I will say though that the FR255S Music I’ve been testing has the most accurate tracking I’ve seen so far in a watch (in just All-Systems mode too, not even Multi-Band). When I look at the maps of my runs in the app, the route most closely follows the trail of where I actually ran compared to other units.

Data after a run on the Forerunner 255S
Side view of the Forerunner 255S music

If you’re chasing PRs, then you’ll appreciate the additional training metrics on the FR255, including:

  • Training Status: whether your training is productive
  • Training Load: whether your training a smart amount
  • Training Effect: how each activity is expected to improve your fitness (aerobic and anaerobic)
  • Course- and weather-specific race predictor: exactly what it sounds like; you can also see how your general predicted finish times have trended over time
  • Heart Rate Variability (HRV) status: tracks the variation in time between heartbeats at night, which informs and improves metrics like Training Status

There are also these features that aren’t performance-based, but may improve the quality of your fitness tracking.

  • Pulse Ox: blood oxygen saturation, which can be helpful to know at high altitudes and during sleep
  • Gyroscope: improves swim feature performance and rep counting for gym activities

Another benefit the FR255 has over the FR55 is the barometric altimeter. The FR55 has a GPS-based altimeter, which tends to be less accurate. This barometric altimeter is also what allows the FR255 to track Floor Climbing.

If you want more accurate elevation stats and real-time elevation data during certain activities (like trail running and hiking), you’ll want to opt for the FR255. If you only care about accuracy and mainly do road running, then the GPS altimeter of the FR55 is probably fine. You can always correct your elevation data on Strava after the fact, using their Basemap.

To help you measure your running intensity, the Forerunner 255 also has wrist-based running power. Running power takes into account your pace, vertical oscillation, grade, and wind conditions to calculate the amount of power you’re applying to the ground as you run. This metric can help you better pace yourself.

Finally, the FR255 has some helpful lifestyle features. If you buy the music version of the watch ($50 more), you can download tracks or use Spotify Premium, Amazon Music, Deezer, or iHeartRadio. You’ll then be able to listen to music from your watch with Bluetooth headphones, and won’t need to bring your phone on runs anymore. You’ll also be able to get Audio Prompts through the headphones and won’t need the Garmin Connect App for them.

You can also make contactless payments with Garmin Pay, which is compatible with most major banks. This can come in handy if you’re on a long run and need to stop and grab fuel, or if you’re simply out and don’t have your card on you.

To help you stay completely in-tune with your body, the Forerunner 255 has a morning report, which summarizes your sleep, recovery, training, and HRV status when wake up. You can customize the report to add or subtract other features like Body Battery, weather, menstrual cycle, and more.

The Bottom Line

Overall, the Forerunner 55 is a solid entry-level watch, especially for those who are mainly road runners. I bought it for my mom, after all! The battery life is good, you’re able to track the most common fitness activities, and you get some performance metrics like Race Predictor and Recovery Time.

But if you’re a trail runner or triathlete, you’ll want to look into the Forerunner 255. You’ll be able to have more accurate elevation readings and GPS tracking options, as well as the ability to track open water swimming and multisport. (A quick note: if the Forerunner 255 is out of your price range and you still want triathlon capabilities, I recommend the COROS PACE 2, which is $200. I personally own a COROS and feel that it’s only right to mention this since it’s the same price as the FR55).

If you’re also especially serious about your performance, you may also appreciate the additional training metrics of the Forerunner 255, which will help you optimize your workouts, recovery, and race plan.

Where to Buy the Forerunner 55 or 255

If this review helped you, it would mean a ton if you purchased through my affiliate links. I also want to encourage you to buy secondhand or from small, local running stores if you can. I don’t get paid if you do that, so if you still want to show your appreciation financially, you’re welcome to buy me a virtual coffee.


Forerunner 55
Forerunner 255


Forerunner 55
Forerunner 255

Other retailers

Swappa (used electronics)

If you have any questions, feel free to leave them in the comments. Also let us know what you picked and why!

You may find these other posts helpful:

Forerunner 55 vs. 245
Forerunner 55 vs. COROS PACE 2

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  1. Can the 255 take pre-loaded maps. And then use as a navigation tool,running in new places? I have the 55 and that feature is not available. Like to ‘design’ my training run and stick to the route.

  2. Hi, I want to buy a Garmin for cycling, I like it simple end effective but can’t decide weather to pick the 55 or 255. I don’t really care about the extended running features, just want to know if the 55 is good for cycling and if the 255 has more cycling features than the 55 or are the same in this aspect? Thanks.

    1. Hi Jack! Both track indoor and outdoor biking, but the FR255 also tracks Mountain Biking, eBiking, and eMountainBiking. It’s also power meter compatible and you can create and follow courses.

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