The Forerunner 45 and 245 were released around the same time and focus on providing runners with great training features and tracking. While they both track other activities, The FR 245 and FR 45 were designed to work best as pure running watches.
The main differences between the FR 245 and the FR 45 are the advanced features and slightly improved hardware on the FR 245.
The FR 245 has double the battery life, more customization options with the watch and data display, basic navigation functions, analyzes your running form,
There is about a $100 difference between these two watches with the mid-range FR 245 coming in around $300 ($350 for the music option) and the budget-friendly FR 45 coming in at $200.
Both the FR 45 and FR 245 have a nice casual look and appear pretty similar.
As far as coloring, you can get the basic FR 245 in black or berry while the basic FR 45 comes in black or lava red.
Earlier versions have corners while both of these watches have rounded and smoothed edges. The gorilla glass case on the FR 245 is hardier and more durable than the FR 45.
The watches are lightweight and fit very comfortably on your wrist. Garmin took weight into consideration with these as the FR 245 has a total weight of 1.3 oz and the FR 45 a weight of 1.2 oz, which are comparatively light to similar options on the market.
The FR 245 also comes with Garmin’s standard quick-release silicon band, which is great for ease of taking the watch off and replacing the band. On the other hand, the FR 45 band is screwed on so changing out the band is a little bit more work.
The screen size on the FR 245 is slightly larger at 1.2 inches than the smaller FR 45 at 1.04 inches. The FR 45 does come in two sizes, and you can opt for a slightly smaller watch overall with the FR 45S (39mm versus 42mm).
You also get a better screen resolution with the FR 245 (240 x 240 pixels versus the FR 45 at 208 x 208 pixels).
The FR 245 has double the battery life of the FR 45, which only has 13 hours. For all the ultrarunners this change is great! You can expect 24 hours with the FR 245 in normal GPS mode, and 24 hrs+ with Garmin’s UltraTrac mode.
For normal everyday usage in smartwatch mode, both watches will last up to 7 days.
Customization is one of the features on the FR 245 that the FR 45 is lacking. All screens can be customized with the FR 245. It’s easy to customize the FR 245 with the app on your phone, and you can change everything from your activity list and widget loop by changing the appearance or re-ordering locations of these items.
With the FR 45, you can only change out watch faces, which is still a good basic minimum customization option.
The menus are fairly similar with both watches and Garmin has made the menu interface more intuitive and easier to use on both.
Although both watches are designed to help you improve your running, you get a variety of other activities and stats. You can keep up to 6 different types of activity tracking loaded on the watch at one time.
These include strength, cardio and elliptical training, and even yoga. With the lack of a barometric altimeter in both watches, you won’t get stair tracking.
Sleep tracking is great at detecting sleep automatically and the watches break down your sleep into 4 stages, including deep, light, REM, and awake.
Tracking and providing you with training tools for your runs is what the FR 245 and FR 45 were made for and they both perform these roles well.
By setting the type of run on your watch, you improve your run tracking accuracy. The FR 245 has run, walk, indoor track, treadmill, and trail running modes. The only mode missing from the FR 45 is the trail running mode.
The GPS sensors on both watches record outdoor runs with great accuracy. If you run with GPS+GLONASS, you’ll get even higher accuracy especially when you are running with poor sky visibility. You will sacrifice battery life for higher accuracy results.
Both of these watches provide metrics that help you become a better runner during and after your run. These include distance, pace, time and cadence.
After a run you’ll also see average and max heart rate as well as aerobic and anaerobic training effect. Your heart rate is broken down into zones and you will see how much time you spent in each zone.
In order to get accurate indoor running on a treadmill, both watches let you manually calibrate distance after 1 mile. Keep in mind that a footpod will increase accuracy on a treadmill by tracking cadence. You also have the option of choosing indoor track. These watches do get GPS lock on inside and track fairly accurately.
Both the FR 245 and FR 45 were designed to track cycling. You have the option of choosing biking or indoor biking.
You can track distance, time, laps, as well as average and maximum speeds. The watch will give you training effect information and show you similar information that you get from running.
If you want to track swimming, the FR 245 is your only option. While both watches hold up fine underwater up to 50 meters, the FR 45 has no swim tracking. The FR 245 will help you record basic stats, but isn’t built for in-depth swim training.
The FR 245 tracks pool swims only, something to keep in mind if you are an open water swimmer. You’ll get metrics to include distance, pace, stroke count/rate, calories burned, and swim efficiency (SWOLF). The watch will automatically recognize freestyle, backstroke, breaststroke, and butterfly strokes.
You still won’t be able to track your heart rate with the included optical heart rate monitor on the FR 245, so plan to use a chest strap if heart rate monitoring is important to you for swimming.
These watches adjust to your activity with auto goals based on your activity level. You’ll get automatic rep counting for strength conditioning. You’ll also get stats like body battery and stress level to track your energy reserves. Both also use your VO2 max to calculate a fitness age for you.
Both watches have similar upgraded hardware. Both have the same heart rate monitor and accelerometer. You will also get a compass in the FR 245 that isn’t included in the FR 45, which is a nice feature to help you explore new areas you’re unfamiliar with but isn’t absolutely necessary.
Note that you don’t get a barometric altimeter with either watch, as in some of Garmin’s higher-end watches. This means your elevation tracking isn’t as accurate with both watches.
HEART RATE MONITOR
The heart rate monitors on the FR 45 and FR 245 are almost identical. Both include Garmin’s new elevate optical sensor, which is very accurate and comfortable as it sits flush against your skin.
You’ll be able to see your HR zones, receive HR alerts, and get calorie estimates from your HR. Recovery time is also estimated based off this sensor.
The main difference here is the SPO2 measurement (also known as Pulse Ox) that is only included with the FR 245, which checks how well your heart is pumping oxygen through your body. You’ll see this displayed as a percentage and it will help you understand how your body is adjusting to your training.
The 3-axis accelerometer in both the FR 245 and FR 45 are very accurate. This sensor helps accurately track when you are running inside. It is self-calibrating, and the accuracy of your speed, distance, and cadence improves once you run outside a few times and calibrates with the GPS.
INTERVAL TRAINING / ADVANCED WORKOUTS
Both the FR 245 and FR 45 allow you to create interval workouts based on time and distance. Create your own custom workouts or sync workouts to your watch with the Garmin Coach function, making it easy to train for specific races and distances.
These functions really set these running watches apart from other brands of activity trackers on the market, with the ability to design and follow custom running workouts.
We like creating workouts in the app and syncing to the watches, as the app is more intuitive. These workouts also adjust to you and Garmin connects you with free training plans that help you meet your time and distance goals.
TRAINING STATUS & LOAD
When trying to understand how training impacts your performance, Garmin hits the mark with the FR 245, a feature notably missing from the FR 45.
Both watches estimate your recovery time through the training load feature, which takes the past week of post-exercise oxygen consumption into account.
You’ll see an estimate of either hours or days for your body to recover after exercise in order to plan workouts without over or under-doing it.
The virtual partner is a new Garmin feature that allows you to race against a desired pace, showing you how far ahead or behind you are. The FR 245 has this virtual partner feature that displays your time and also shows your average pace in comparison to the theoretical racer.
If you want to race against a previous activity, you can choose your virtual partner from your own history!
The biggest difference here is the virtual pacer feature on the FR 45, which displays if you are ahead or behind the pace you set but unlike the FR 245, you can’t choose to race against previous activities you’ve recorded.
MAPPING / NAVIGATION
Basic mapping and navigation are only available on the FR 245. You still don’t get robust features of some of Garmin’s higher-end models with no topo map, but you can still set a navigation course.
You’ll see navigation information as you start your run and be able to zoom in to make looking at your course easier. At the end of the day, you get a basic breadcrumb map.
By connecting to the Garmin Connect App, you can enable great safety features with both watches. The safety features are very similar with both the FR 245 and FR 45 and give you some options when it comes to getting in contact with someone if you need help. For both, you need your phone to be connected to your watch with bluetooth for the safety features to work.
Incident Detection detects an incident while cycling or running and automatically notifies a preset contact in your phone.
Safety Assistance lets you send a preset text with your name and GPS coordinates to an emergency contact.
LiveTrack lets anyone you invite to follow your run with data. If you happen to have an Android, you can even enable Live Event Sharing which gives real-time updates to friends and family during an event, like a race.
The standard versions of both of these watches come with some great accessories. While neither have music storage (you can pay $50 more and get music storage with the FR 245 Music), you can still control music with both watches as long as you have with your phone with you.
While the FR 245 is compatible with both bluetooth and ANT+ accessories, the FR 45 is only compatible with ANT+ accessories, so consider if you already have any bluetooth accessories.
Additionally, both watches will display smartphone notifications and you can see notification alerts directly on the watch itself.
RUNNING DYNAMICS POD
The FR 245 provides you with some great data to improve your running form that isn’t supported with the FR 45. By adding a Running Dynamics pod to your waistband, you can improve your running form with helpful metrics.
The watch analyzes your stride length, ground contact time and balance, as well as vertical oscillation and vertical ratio.
With the FR 245, you have the option to add a power meter. Power meters can run upwards of $1,000, so it’s best to do your research if you are interested in purchasing one. If cycling stats are important to you, this is one of the things you miss out on with the FR 45.
You can also add a cycling speed and cadence sensor for about $70 with both of these watches, however, the sensor must be ANT+ capable for the FR 45, not bluetooth, which the FR 245 also supports.
If you are looking for a pure running watch to train with and want to have the option to run ultras or are looking for extended battery life, the FR 245 is a good pick. You still get a majority of the training options with the FR 45.
Consider the importance of basic navigation and maps, if you want recovery information, or to record basic stats on swimming. If these are important features, the FR 245 is your best bet, otherwise the less expensive FR 45 is a great value for your money.