Garmin Forerunner 645

Based on 146 reviews

The Looria Grade (A - F) accounts for multiple factors, including sentiment, helpfulness, and more. Learn about our sources and ranking.

  • Great for running
  • Simple to use
  • Feature loaded
  • Accurate when measuring heart rate from the wrist
  • Amazing technology


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I have had a Forerunner 645 Music for 2.5 years and the plastic where the strap hooks onto the watch broke. It is part of the molded plastic body of the watch so it's not repairable. I thought I'd give Garmin support a call and see what they could do and they said they can replace it with a refurb watch for NZD$165 because it's no longer a current product.
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It's not the silver bullet, but it's closer than most.
A little bit about me: I am a fairly average guy. Not a triathlete and probably not training for a marathon. I am just a middle-aged guy fighting against the natural descent into dad-bod slothdom. I go to the gym 3-4 days a week and mostly swim and do some weights, kettlebells, etc. I "run" once in ...
Evul Jeenyus
5 years ago
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No issues with lighting at night nor when sleeping. The battery is also very good. Charges fast and lasts a long time. Never had it go to 0 but I think I've used it about a week without charging so far.
Didn't feel great when I woke up during the night, but not a day off work bad. I had done a fairly tough interval run in the morning and got the jab at 4pm, planning on resting for two days and a 1hr+ run on Thursday, depending on how I feel, have a virtual marathon in under two weeks but not too concerned about times. To be honest I'd never really thought much about the body battery readings, only just upgraded from a 2 year old 645 and had a 30 before that, but it honestly reflected how I felt in the morning.
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Forerunner 645 heavily discounted, bargain?
As an owner of a 645 - buy something else! :D. We were promised we were getting the top of the range running watch (745/945 are considered multisport). To be fair it was top of the range, for about 3 months, then they announced the lower range watches were moving to new hardware and getting more features!.
About time, Garmin
This watch is exactly what I’ve been waiting for, I’ve had it for almost 3 weeks and it’s perfect for my needs. I typically run 20-25 miles per week and was sick of carrying my phone to listen to music. Within 10 minutes of opening it, I had it loaded with my running playlist and was out the door. S...
4 years ago
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Forerunner 645 music. Jaybird X4. The experience is terrible. To the point where i think its not okay that it was advertised with this feature at all.
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Garmin running watches
I have used the Vivoactive 3 for two years and use the forerunner 645 music now...the Vivoactive is incredibly annoying for running. I find it that I was in need of a running watch first and not e-watch if you catch my drift.
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FR645 v FR55
To be honest 645 is very decent watch and it comes down on what you need. I have sold my ubertech 945 and bought old 735xt (with older hw and from year 2016). Reason was simple - I was not using all features of 945 so I sold my 945 for 500usd, bought 735xt for 100usd and saved 400 usd ;) 735xt has all the metrics I need.
Buyer beware
Thought this watch was discounted 30.00 for amazon. Come to find out after many calls to Garmin it’s a Asian version that is not compatible for many headphones, music and updates. I never saw any disclaimers on the description. I would have paid the extra 30.00 for a USA compatible watch.
4 years ago
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Screen Size

1.2 Inches

Special Feature


Connectivity Technology