Garmin Forerunner 645 vs Vivoactive 3 Music – Product Comparison

Garmin Forerunner 645 vs Vivoactive 3 Music – Product Comparison

This is a product battle between the Garmin Forerunner 645 vs Vivoactive 3 Music

While they are both extremely versatile GPS watches, there are some key differences between the two units.

To help you understand which watch is better suited to your needs, we’re going to unpack all the key similarities and all the key differences. But before we do, it’s worth pointing out the biggest differences, right off the bat.

Key Difference 1: The Forerunner 645 supports Garmin advanced running dynamics and Garmin Running Power. This is ultimately why it is a better choice for runners. However, you do need to purchase one of the following 3 accessories in order to unlock advanced running dynamics and running power. 

  • Garmin HRM-Run
  • Garmin HRM-Tri
  • Garmin Running Dynamics Pod

Key Difference 2: The Garmin Vivoactive 3 Music has golf tracking built into the watch. This is super handy for golfers, because you basically get an awesome activity tracker that doubles as an excellent golf watch. If you don’t play golf, then obviously this feature shouldn’t affect your choice of watch, but if you do, it could be a gamechanger.

Key Difference 3: The Vivoactive 3 has a touchscreen, whereas the Forerunner 645 relies exclusively on buttons to control the watch. This is one of the reasons that the Vivoactive 3 functions better as a smartwatch, and the the Forerunner 645 functions better as a running watch. 

Basically, the buttons of the FR645 are a bit more user friendly when you’re actually running. However, the touchscreen of the Vivoactive 3 Music is still perfectly fine for most runners, and it feels more like a smartwatch when you aren’t exercising.

Now let’s breakdown all of this info into some super simple tables. 

Garmin Forerunner 645 vs Vivoactive 3 Music - Key Similarities

Forerunner 645


Vivoactive 3



Wrist-based HRM

24/7 Activity Tracking

Sleep Tracking

Stress Tracking

Indoor + Outdoor Running

Indoor + Outdoor Cycling

Indoor + Outdoor Rowing

Pool Swimming

Barometric Altimeter


Garmin Running Coach

Music Storage & Apps

Payments from watch

Bluetooth®, ANT+®, Wi-Fi®

Open Water Swimming

Triathlon Mode

Body Battery Score

Smartwatch Battery

Up to 7 Days

Up to 7 Days

GPS + Music Battery

5 Hours

5 Hours

Garmin Forerunner 645 vs Vivoactive 3 Music - Key Differences

Forerunner 645


Vivoactive 3

Garmin Running Power

Advanced Running Dynamics


Golf Tracking

Total Sports Modes



GPS Battery Life

14 Hours

13 Hours

Forerunner 645 vs Vivoactive 3 - Sports Modes

Forerunner 645 - Sports Modes Vivoactive 3 - Sports Modes
01) Strength Training 01) Strength Training
02) Cardio Training 02) Cardio Training
03) Elliptical Training 03) Elliptical Training
04) Stair Stepping 04) Stair Stepping
05) Floor Climbing 05) Floor Climbing
06) Indoor Rowing 06) Indoor Rowing
07) Yoga 07) Yoga
08) Running 08) Running
09) Treadmill Running 09) Treadmill Running
10) Indoor Track Running 10) Indoor Track Running
11) Skiing 11) Skiing
12) Snowboarding 12) Snowboarding
13) Cross Country Skiing 13) Cross Country Skiing
14) Stand Up Paddleboarding 14) Stand Up Paddleboarding
15) Rowing 15) Rowing
16) Cycling 16) Cycling
17) Indoor Cycling 17) Indoor Cycling
18) Pool Swimming 18) Pool Swimming
19) Golf Mode

It’s pretty clear to see that both watches are very well rounded in terms of the sports modes that they offer.

Naturally the Vivoactive 3 Music claims a small victory in this particular aspect of the battle, because it has golf tracking features, and the Forerunner 645 doesn’t.

However, if you don’t play golf, this is a non-concern, because the FR645 matches the Vivoactive 3 music in every other sports/activity mode. 

Visual Summary of Key Features

Garmin Forerunner 645 - Features Summary

Garmin Vivoactive 3 Music - Features Summary

So which one should you buy?

These watches are about as similar as it gets, technically speaking.

The primary advantages of the FR645 is that it has advanced running dynamics and Garmin Running Power.

The primary advantages of the Vivoactive 3 Music is that it has golf tracking and a touchscreen.

In my honest opinion, it all comes down to this.

The Final Word

Ultimately, the Forerunner 645 is better suited to runners, so if you’re addicted to collecting kilometers, it’s definitely the right choice.

However, the Vivoactive 3 Music has dropped in price quite a lot since it was first released. That makes it a very compelling option, because it’s so similar to the Forerunner 645 in terms of technological features. It’s basically a Forerunner 645, with a touchscreen and golf mode, minus the advanced running stats. 

Leave a Comment