Garmin

Forerunner 645

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Overall

#144 in

Fitness Trackers

according to Reddit Icon Reddit

Sentiment score50% positive
3
1
2

Top Pros

Top Cons

Last updated: May 20, 2026

Reddit Reviews

Reddit IconCorbixz
8 months ago

How quickly does it charge? I've gotten used to popping my Garmin (FR645, FR945, Fenix 7s, then Fenix 7s Pro) on the charger for 10min or so while I shower and that is enough that I never have to worry about the battery. Think the same would be true of the Venu 4?

Reddit IconEmmy_Strange
6 months ago

I had an Apple Watch Series 3 for many years. Then I bought a FR645 to try alongside, just for running. Loved it so much I decided to go full Garmin with a FR745. Loved that watch so much, until I smashed it climbing 🤦‍♀️ Decided to upgrade to a Fēnix 7S SS because I wanted maps and I clearly needed the sapphire glass. I’ve had the Fēnix maybe 2.5 years now. Recently, I thought I might prefer an Apple Watch as I am now dealing with chronic illness and have not been able to engage in any of my usual sporting/outdoor activities for 6 months. I lasted 3 weeks with an Apple Watch Series 11 before coming back to my Fēnix. I just prefer the MIP display, the battery and the buttons. I don’t really care for smart features. Also the workout screens and maps but obviously not using those much right now. Sold the Apple Watch yesterday. No regrets.

Reddit IconFun_Apartment631
4 months ago

Does all the stuff, predates two major price hikes that didn't come with a lot of value-added. The 65 got a new screen and the 70 got a bunch of new metrics that aren't really actionable. Garmin's comparison tool is pretty good, you can line them up and decide for yourself if the newer ones add anything that's worth it to you. In case you missed it, someone else shouted out the 255 which I think is the best value going in a Garmin watch unless you want maps.

10 months ago

Lots of options. Check out the Venu series, Vivofit, and Vivoactive. IMO the value-added aspects of the Forerunner are around running and other aerobic endurance sports. Are those relevant to you?

11 months ago

Forerunner can be a great alternative to Fenix if you're price conscious. Or just last generation Fenix. Do you care about maps?

11 months ago

Forerunner does that stuff too. In general, higher-end Garmins add, they don't take away. Are you serious about any of your sports? Like planning seasons, building for events, that kind of thing?

11 months ago

Changed my mind... I think without an explicit indoor rowing activity profile and VO2max, the extra analysis stuff on the Forerunner won't really work. Not sure if any of the watches have that. I know there are some accepted equations to estimate that stuff, though I think you'd also need a reasonably accurate power meter on your rowing machine. So yeah, Venu or whatever is fine.

11 months ago

My opinion, go with the Forerunner. Check out all the chatter from people moving on from their Apple Watches - I get that some of the newer ones have much better support for running but you say you have an older one. And you're not going to want to carry your phone either. How much running have you done up to now?

Reddit IconImportant_Article_71
10 months ago

Just got a 265 I am happy with

10 months ago

Same here. Loved my 645 but I am happy with the upgrade.

Reddit IconMiguelSTG
4 months ago

FR645 is what's on my wrist, I like the screen color and contrast. I also own a 6x, but the screen was lacking, although the golf function is much better on the Fenix.

Reddit IconPhrexeus
10 months ago

Yeah I've had mine for 6 months or so, it's a great watch and much better than the 645 I had previously. It gives heaps of running dynamics especially if you pair it with a chest strap. It's more than enough for most runners, assuming you don't need navigation/maps.

Reddit Iconshadrach103
8 months ago

Love my 265S and I don't feel like I'm missing anything that the more expensive models offer. I no longer use the third-party arm band that I paired with my old FR 645 as the HRS in the 265 is so much better than the 645 was. GPS tracking is great and initial sync-up only takes a few seconds. I honestly ignore most of the training/recovery crap in the watch as I find it pretty useless. I thought I might not like the AMOLED after using a MIPS watch for years but it I find the AMOLED is great once you get used to the brief wake-up delay.

Reddit Iconspe033
8 months ago

Depends if you're into the data! I've had a forerunner 645 since 2019 and it's still going strong! I love the data and it keeps me motivated! Meanwhile my husband runs every day with no watch and zero concept of how long and fast he runs (I find that crazy, but he's a WAY better runner than I am so obviously it works for him!)

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