Garmin Forerunner 255 vs. 745: Which Should You Pick?

Forerunner 255S in Black next to the Forerunner 745 in Neo Tropic

Since the Forerunner 255 now has open water swimming and triathlon mode, you’re likely wondering if the Forerunner 745 is still worth buying. (The short answer is yes, depending on the price).

In this post, I’ll be breaking down the similarities and differences of these two multisport 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 all the COROS models as well as 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 FR255 or FR745, but I did buy a used FR745 for testing before passing it on, and have had the chance to use a FR255 loaner.

This post contains 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 255 and 745

The Forerunner 255 and 745 have a lot of similar features. Here’s a quick overview of them:

Fitness tracking for common activities: You’ll be able to track a wide variety of indoor and outdoor activities, including:

RunningCardio and Elliptical Training
Indoor + Outdoor Track RunningStair Stepping
Treadmill RunningFloor Climbing
Trail Running (+ Ultra Running)Indoor Rowing
Virtual RunningPilates
Indoor BikingHiking
Mountain BikingSkiing
Pool SwimmingSnowboarding
Open Water SwimmingXC Classic Skiing
Triathlon/MultisportStand Up Paddleboarding

Everyday fitness stats: steps, floors climbed, heart rate, Pulse Ox, stress, sleep, menstrual tracking.

Training metrics: VO2 max, Recovery Time, Race Predictor, Training Status, Training Load, Training Effect, 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, breadcrumb navigation, and Audio Prompts.

Smartwatch features: weather, calendar, messages, Garmin Pay (contactless payments), find my phone, find my watch, Smart Lock (automatically unlock your phone when watch is in range).

Music functionality: download tracks to your watch or use Spotify Premium, Amazon Music, Deezer, or iHeartRadio. Available on the FR255 music version only and the regular FR745.

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)

They do have pretty substantial differences though, so let’s get into those now!

Reasons to Choose the Forerunner 255

Data after a run on the Forerunner 255S
Forerunner 255S music in black lying flat on a white surface

The Forerunner 255 has two size options: there’s 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 (and 17% less than the FR745).

Keep in mind that the FR255S does have a slightly smaller screen size and resolution compared to the FR255 as well as the FR745. Here’s how the three watches compare:

Screen sizeResolutionWeight
FR2551.3″260 x 26049g
FR255S1.1″218 x 21839g
FR7451.2″240 x 24047g

I didn’t have any problems with visibility on the FR255S, but if you’re looking for a larger screen, you may prefer the FR255.

The FR255 also has a music and non-music version. The music version allows you to download tracks to your watch, or use Spotify Premium, Amazon Music, Deezer, or iHeartRadio. You’ll then be able to listen to music 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.

If you don’t need the music capability, you can save $50 ($350 vs. $400). The Forerunner 745 only has one version and it can carry music by default.

The Forerunner 255 has about double the battery life of the Forerunner 745, making it a wiser choice if you plan to do ultra endurance events, or don’t want to charge your watch often. Here’s a breakdown of the battery life:

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.

For the Forerunner 745, you can expect up to 7 days of battery life in smartwatch mode, 16 hours in GPS mode, 6 hours in GPS mode with music, and 21 hours in UltraTrac mode.

Some of the terms in the above table may sound like gibberish, so let me explain. “GNSS” stands for Global Navigation Satellite System. “All-Systems” lets the Forerunner 255 use any of the satellite systems (GPS, GLONASS, Galileo, BeiDou, QZSS) and switch between them based on the quality of their signals. This is the default setting for the watch. “Multi-Band” is the dual-frequency option that allows your watch to get L1 and L5 frequency signals, improving tracking accuracy.

The Forerunner 745 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 FR745 is still accurate, so these additional tracking options may only make a significant difference if you’re training a lot in cities with skyscrapers or remote areas with poor signal.

Side view of the Forerunner 255S music
Heart rate sensor of the Forerunner 255S

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. So if GPS accuracy has been an issue for you in your area, this could be a big perk of the watch.

If you rely on metrics like Training Status to inform your workouts, you may appreciate that the Forerunner 255 has Heart Rate Variability (HRV) status, which tracks the variation in time between heartbeats when you sleep. HRV is factored into Training Status, making it more accurate. When you maintain a good balance between training and recovery, your HRV will be balanced.

The Forerunner 255 tracks these activities that the Forerunner 745 doesn’t:

  • HIIT
  • eBiking
  • eMountain biking

If racing is a big motivator for you, you’ll like the new race widget, which offers you training tips, personalized daily suggested workouts, and finish time predictions based on the course, weather, and your training.

While the Forerunner 745 also has Race Predictor, you’ll be able to see how your predicted finish times have trended over time on the Forerunner 255.

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 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.

Reasons to Choose the Forerunner 745

Forerunner 745 in mind on my wrist with the menu screen
Forerunner 745 in mint resting flat on a white surface

The Forerunner 745 is part of a more premium lineup than the Forerunner 255, but now that the FR255 has open water swimming and multisport modes, the Forerunner 700 series may become obsolete (we may never see a Forerunner 755, though there’s no official word out yet).

Still, the Forerunner 745 is a solid choice, and it’s not that dated, having been released in September 2020. Because it’s a bit older, you’ll probably be able to find it at a steep discount on secondhand markets. In fact, I’ve seen it go for under $200 on apps like Mercari (referral link for $10 off), though average prices seem to be closer to $225-300. I personally sold mine to my brother’s friend for $250, though I bought it the year before for $360.

This is one of the biggest reasons you may prefer the FR745 over the FR255. If you can get the Forerunner 745 for $250 or less, you’re getting very similar functionality to the FR255 for a fraction of the cost.

So what does the Forerunner 745 have that the Forerunner 255 doesn’t? There are a few more tracking profiles it covers:

  • Backcountry skiing
  • XC skate skiing
  • Kayaking
Forerunner 745 in mint with the back facing up lying flat on a white surface
Forerunner 745 in mint lying on a white surface and showing the side profile with 3 buttons

While both the FR745 and FR255 music have WiFi functionality, the non-music FR255 doesn’t. WiFi is what allows you to initially connect to those music apps and download your playlists to be played offline. It can also be handy since your activities can automatically sync via WiFi, and you won’t have to wait for Bluetooth connectivity (you can just return home from a run and your stats will get uploaded to Garmin and synced to Strava).

Physically, the Forerunner 745 is said to have a more premium screen, made with Corning Gorrilla Glass DX vs. the Forerunner 255’s Corning Gorrilla Glass 3. Both types of glass are known to be strong and durable, but the DX version has less reflection.

I didn’t have an issue with reading the screen of the FR255, but I did notice that it was harder to take photos of it due to the reflectiveness of the glass. This probably is a non-issue for most people, unless you have a running social media account (and even then, you just have to find the right angle).

If you like guided workouts, you can download cardio, strength, yoga, Pilates and HIIT workouts from the Garmin Connect app and follow them on-screen on your watch.

Finally, the Forerunner 745 offers GroupTrack, which is the group version of LiveTrack. If you plan to do group bike rides, this can be helpful for keeping track of everyone. You can see where your Garmin Connections are during their activity on your phone.

The Bottom Line

The Forerunner 255 and 745 are very similar watches. If you’re mainly a road runner or triathlete, you can’t really go wrong with either.

If you plan to do longer events, have a small wrist, or live in an area with spotty GPS signal, then the Forerunner 255 is a better choice. If you’re really into training data, you’ll also appreciate the additional features like the race widget, HRV status, and running power.

If you do backcountry skiing or group bike rides, then you may prefer the Forerunner 745.

I personally lean towards the Forerunner 255 since I have small wrists and am used to the longer battery life of the COROS ecosystem. When I had the Forerunner 745 and tested it on a few runs each week, I had to charge it every 4-5 days. With the Forerunner 255S, I’m usually able to get 1.5 weeks battery out of it, tracking a few runs each week with no music (I don’t enable smartphone notifications, and keep the watch turned on all the time, but only wear it for runs).

Of course, this is only if cost isn’t an issue. I’d say the Forerunner 745 is better value than the Forerunner 255 if you can find one in good used condition for under $250. $300 is probably the max price I’d pay today since used watches don’t come with warranty, and at that rate, you’re getting close to the price of a new FR255.

If you’re buying new at full retail price (or the prices of the watches are pretty much the same), then I’d point you towards the Forerunner 255 without a doubt.

Where to Buy the Forerunner 255 and 745

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 255
Forerunner 745


Forerunner 255
Forerunner 745

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 745 vs. 955
Forerunner 255 vs. 955
Garmin Forerunner 745 vs. COROS APEX Pro

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