Image source: Garmin

Garmin Forerunner comparison: choosing the right sports watch

Garmin has recently introduced a number of new GPS watches to its Forerunner line. This includes the 45/45S, 245/245 Music and 945. There are still 6 devices across the entire range but they are now more modern looking and come with some additional smarts. Here’s our comparison on how they stack up.

Essential reading: Which Garmin fitness tracker should you buy?

With so many sports watches on offer, you might be confused on which on is right for you. Hopefully the guide will help.

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Forerunner 35 | Forerunner 45 | Forerunner 245 | Forerunner 645 Music | Forerunner 735 XT | Forerunner 935 | Forerunner 945

Garmin Forerunner comparison

Forerunner 35

Guide to choosing the right Garmin Forerunner watchPros: Affordable, built-in GPS, excellent battery life
Cons: No altimeter, B&W screen, few advanced performance metrics

This entry-level Forerunner watch is for those on a budget. It features Garmin’s Elevate wrist heart rate technology. This will help you to heart-rate zone train and like most Garmin devices, it will keep tabs on the all-important resting heart rate.

There’s also built-in GPS for phone free training, but no support for GLONASS/GALILEO. Built-in GPS adds to the price but is a worthwhile investment.

Garmin has thrown in a few advanced performance stats, too. This includes VO2 max and Fitness Age.

Thanks to an accelerometer, the timepiece doubles-up for 24/7 activity tracking and will count steps, calories and distance throughout the day and sleep at night. The move bar with vibration alerts motivates you to get up from the sofa when you’ve been chilling for too long.

You’ll also find some smartwatch features such as smart notifications and audio prompts, as well as customization options and, like all Garmin Forerunner watches, excellent battery life.

Amazon | Garmin*

Foreunner 45/45S

Guide to choosing the right Garmin Forerunner watchPros: Affordable, full-color screen, Body Battery function
Cons: No altimeter, few advanced performance metrics

This is another option for those looking for an affordable entry into the world of running watches. The device essentially replaces the Forerunner 35. For some reason, though, Garmin is still selling both. The two iterations include a small 45S (39.5 x 39.5 x 11.4 mm) and large 45 (42 x 42 x 11.4 mm) model.

Unlike the B&W screen of its predecessor, the display of the 45/45S is full color. Garmin has also moved from a rectangular screen to a circular one. There are lots of small improvements including GLONASS/GALILEO support.

The watch also comes with Garmin’s new Body Battery function. This taps into heart rate variability (HRV), sleep and activity data to give you an indication of your body’s energy levels.

An interesting addition is incident detection. If the watch assesses you’ve had an accident, the app will send an automated text message and email with your name and GPS location to your emergency contacts. The watch uses your paired compatible smartphone to do this.

We suggest going for this one if you’re after a budget running watch instead of the Forerunner 35. It retails only for around $30 more but the added features are worth it.

Amazon |Garmin*

Forerunner 245/245 Music

Guide to choosing the right Garmin Forerunner watchPros: Designed for more serious runners, Lots of advanced performance metrics, Pulse Ox sensor, Music storage option
Cons: No altimeter

This is a more fully featured watch that replaces the extremely popular Forerunner 235.

In addition to everything the lower specs devices offer, the 245 comes with some more advanced performance metrics. This includes Recovery Time, Race Predictor, Performance Condition, Anaerobic/Aerobic Training Effect, Training Load, Training Status and more. Needless to say, having this type of information takes analysis of your workouts to a whole new level.

The other additions are a PulseOx sensor and compass. Interestingly, the 35, 45 and 245 all lack a barometric altimeter for counting floors. A PulseOx sensor is a worthwhile upgrade as it tracks your blood oxygen level. This is mostly during the night for more advanced sleep statistics, although manual readings can be taken throughout the day.

All in all, this is a well rounded watch for the price that will easily meet the needs of most runners. You can also opt for 245 Music, the exact same device but with local storage for up to 500 songs.

Amazon | Garmin*

Forerunner 645/645 Music

Guide to choosing the right Garmin Forerunner watch

Pros: Music storage option, NFC for Garmin Pay
Cons: No Pulse Ox sensor, no Body Battery function

Now more than a year old, this is the first Garmin device to offer built-in storage for Music. There are actually two iterations to chose from, one with and one without music.

The watch comes with a barometric altimeter, gyroscope and thermometer. You won’t find these on the Forerunner versions mentioned above. It lacks, though, the PulseOx Sensor of the 245.

As shown in the table below, there are other differences to be aware of such as a few more performance stats. The watch doesn’t feature the Body Battery and Incident detection functions as they were released after it came out.

What it does have is an NFC chip Garmin Pay. On your way back from your run, you can now treat yourself to a well earned snack – no cash or credit card needed.

Amazon | Garmin*

Forerunner 735XT

Guide to choosing the right Garmin Forerunner watchPros: Its price is coming down, multi-sport support
Cons: Nearly three years old now, lacks some sensors and advanced performance metrics

The oldest device on this list, the 735XT was released in mid-2016. It’s still a pretty good watch, though, a testament to the quality of Garmin-made products.

The 735 XT is actually cheaper than the 645 and on par in terms of price with the 245. Seeing that is bound to be phased out soon, it may become heavily discounted in time.

Nevertheless, we suggest going for one of the newer devices. The 735XT lacks the barometric altimeter, gyroscope, thermometer and PulseOx sensor, some advanced performance metrics and newer features such as Body Battery and Incident detection.

It does come, though with multi-sport support and additional sports profiles such as open water swimming and additional cycling features.

Amazon | Garmin*

Forerunner 945

Guide to choosing the right Garmin Forerunner watch Pros: Built for fitness freaks, comes with everything Garmin has on offer, multi-sport support, full-color on-board maps
Cons: Price

We’ve come to the daddy of the bunch, the Forerunner 945. It does pretty much everything the other ones on this list do, and slaps on some more advanced performance stats and support for additional sports. This includes golf and outdoor recreation (Hiking, Climbing, Skiing, Snowboarding, XC Skiing, Stand Up Paddleboarding, Rowing, Kayaking). Music memory is also larger allowing storage for up to 1,000 songs.

Built for those serious about training, the watch comes with advanced physiological features. Training status now has adjustments for heat and altitude acclimation status. There is training load focus which separates your training load into different categories, recovery time, and more detailed aerobic and anaerobic training effects.

The other important upgrade are full-color, onboard maps that guide you on your run so you never get lost. This is similar to what you get on the most recent Fenix line.

The Forerunner 945 is the one to go for if you want the best running/triathlon watch on the market today. It is a bit pricey so another option is to opt for its predecessor – the 935.

Amazon | Garmin*

Garmin Forerunner comparison

Guide to choosing the right Garmin Forerunner watchGuide to choosing the right Garmin Forerunner watch Guide to choosing the right Garmin Forerunner watch Guide to choosing the right Garmin Forerunner watch Guide to choosing the right Garmin Forerunner watch
Forerunner 45/45SForerunner 245/245 MusicForerunner 645/645 MusicForerunner 735XTForerunner 945
Color display
Auto pause feature
Auto lap feature
Auto/manual multisport
Personal records
Virtual Partner/pace alerts
Heart rate-based calorie computation
Customizable screen (s)
Advanced workouts
VO2 max estimate
Recovery time
Race predictor
Connected features
Step counter
Auto goal
Move bar
Sleep monitoring
Wrist based heart rate
Connect IQ storeWatch faces only
Advanced running dynamics
HRV stress test
Strava Live Segments
Lactate threshold
Performance condition
Anaerobic training effect
Aerobic training effect
Training load
Training status
Training load focus
Pulse Ox sensor
Music245 Music only645 Music only
Garmin Pay service
Metal bezel
Bike power
Cycling dynamics
Shimano Di2
Open-water swim activity
HRM-Swim support
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