Garmin Forerunner 645 Specs (Detailed) – Comparison To 735XT and 935

The Garmin Forerunner 645 is listed on Garmin’s website with the detailed specs BELOW.

Garmin 645

Clicks to source. When the original is removed this image will disappear too.

The information now looks solid and the specifications are broadly ‘as expected’ several weeks ago.

A formal Garmin announcement is not now likely until CES2018.

This looks to me like the basic physical hardware of the Vivoactive 3 (with more buttons and no touch screen 😉 ) but also most tasty features of the Fenix 5/Forerunner 935 thrown in; perhaps warranting an upgrade from your Forerunner 630?

I’ll summarise the important differences and then you can read throught the detailed specs and comparisons, further below

Opinion

  • It looks to have everything a running watch could ever ‘need’.
  • The bits of functionality it ‘misses’ out on are not core to running.
  • Personally I would prefer a sports watch appearance, but Garmin have probably made the right call with this design for the broad target market of runners
  • It’s expensive BUT the onboard MUSIC could make this a ‘Kerching moment’ for Garmin’s accountants.
  • The Forerunner 645 is clearly different from other Garmins in the Forerunner range.

Summary

  • New format compared to style of the Forerunner 630 / 235
  • Strong glass and overall ‘lightweight’
  • Standard bands
  • Same screen resolution as the Fenix 5/935 at 240x240px
  • Battery life looks low.
  • Lots of connectivity – probably every key function
  • Music with c800 onboard songs and BLE headphone connectivity
  • Garmin Pay (contactless effectively won’t be widely avaialble until 2018)
  • It’s a cycling watch BUT it will NOT support your power meter
  • It’s a pool swim watch BUT will not cache underwater HR from HRM-TRI. Not really designed for open water use with restricted functionality there.
  • It’s not a triathlon watch ie it does not have multi-sport profiles
  • It has no golf abilities
  • It has more limited hiking-type functionalities compared to the 935./Fenix 5
  • It has all the activity tracking functionality.
  • Supports both BLE and ANT+ sensors
  • Has all the clever Firstbeat physiological functionality
  • ‘Obviously’ it will support Garmin’s Running Power.

 

 

Garmin Forerunner 645 Music Garmin Forerunner 735XT Garmin Forerunner 935
Top-end running Watch Tri-Lite Watch Super Tri Watch
Headline RRP USA $450 $350 $500
General
Lens Material Corning® Gorilla® Glass 3 chemically strengthened glass chemically strengthened glass
Bezel Material stainless steel fiber-reinforced polymer
Case material fiber-reinforced polymer
QuickFit™ watch band compatible yes (22 mm)
Quick Release Bands yes (20 mm, Industry standard)
Strap material silicone silicone silicone
Physical size 42.5 x 42.5 x 13.5 mm 44.5 x 44.5 x 11.9 mm 47 x 47 x 13.9 mm
Weight 42.2 g 40.2 g 49 g
Water rating 5 ATM 5 ATM 5 ATM
Display type sunlight-visible, transflective memory-in-pixel (MIP) sunlight-visible, transflective memory-in-pixel (MIP) sunlight-visible, transflective memory-in-pixel (MIP)
Display size 1.2″ (30.4 mm) diameter 1.23″ (31.1 mm) diameter 1.2″ (30.4 mm) diameter
Display resolution 240 x 240 pixels 215 x 180 pixels 240 x 240 pixels
Color display  Yes   Yes   Yes
Battery life Smartwatch Mode: Up to 7 days Smartwatch Mode: Up to 11 days Smartwatch Mode: Up to 2 weeks
GPS mode with music: Up to 5 hours GPS mode: Up to 14 hours GPS/HR mode: Up to 24 hours
UltraTrac™ mode: Up to 24 hours without wrist heart rate UltraTrac™ mode: Up to 60 hours without wrist heart rate
Memory/History 200 hours of activity data 80 hours of activity data 64 MB
Clock Features
Time/date Yes Yes Yes
GPS Time Sync Yes Yes Yes
Automatic daylight saving time Yes Yes Yes
Alarm clock Yes Yes Yes
Timer Yes No Yes
Stopwatch Yes Yes Yes
Sunrise/sunset times Yes Yes Yes
Face It™ watch face creator Yes Yes Yes
Sensors
GPS Yes Yes Yes
GLONASS Yes Yes Yes
Garmin Elevate™ wrist heart rate monitor Yes Yes Yes
Barometric altimeter Yes No Yes
Compass Yes Yes Yes
Gyroscope Yes No Yes
Accelerometer Yes Yes Yes
Thermometer Yes No Yes
Daily Smart Features
Connectivity Bluetooth®, ANT+®, Wi-Fi® Yes Bluetooth® Smart, ANT+®, Wi-Fi®
Connect IQ™ (downloadable watch faces, data fields, widgets and apps) Yes Yes Yes
Smart notifications Yes Yes Yes
Text response/reject phone call with text (Android™ only) Yes No No
Calendar Yes Yes Yes
Weather Yes Yes Yes
Music controls Yes Yes Yes
Plays Onboard Music Yes No No
Music Storage up to 800 songs No No
Find My Phone Yes Yes Yes
Find My Watch Yes Yes Yes
VIRB® remote Yes Yes Yes
Smartphone compatibility iPhone® and Android™ Yes iPhone®, Android™, Windows®
Compatible with Garmin Connect™ Mobile Yes Yes Yes
Garmin Pay™ Yes No No
Activity Tracking Features
Step counter Yes Yes Yes
Move bar (displays on device after a period of inactivity; walk for a couple of minutes to reset it) Yes Yes Yes
Auto goal (learns your activity level and assigns a daily step goal) Yes Yes Yes
Sleep monitoring (monitors total sleep and periods of movement or restful sleep) Yes Yes Yes
Calories burned Yes Yes Yes
Floors climbed Yes Yes Yes
Distance traveled Yes Yes Yes
Intensity minutes Yes Yes Yes
TrueUp™ Yes Yes Yes
Move IQ™ Yes No Yes
Fitness Age yes (in app) No yes (in app)
Fitness Equipment/Gym
Preloaded gym activity profiles Strength Training, Cardio Training, Elliptical Training, Stair Stepping, Floor Climbing, Indoor Rowing and Yoga Indoor Rowing, Strength Training and Cardio Training
Cardio workouts Yes Yes
Strength workouts Yes Yes
Automatic rep counting Yes Yes
Training, Planning and Analysis Features
GPS speed and distance Yes Yes Yes
Customizable data pages Yes Yes Yes
Customizable activity profiles Yes Yes Yes
Auto Pause® Yes Yes Yes
Advanced workouts Yes Yes Yes
Downloadable training plans Yes Yes Yes
Auto Lap® Yes Yes Yes
Manual lap Yes Yes Yes
Virtual Partner Yes Yes Yes
Configurable lap alerts Yes Yes Yes
V02 max Yes Yes Yes
Training Status (lets you see if you’re training effectively by tracking your training history and fitness level trend.) Yes No Yes
Training Load (your total training load for the last 7 days calculated from estimated EPOC) Yes No Yes
Training Effect (aerobic) Yes Yes Yes
Training Effect (anaerobic) Yes No Yes
Customizable alerts Yes Yes Yes
Audio prompts Yes Yes Yes
Finish time Yes Yes Yes
Race an Activity Yes Yes Yes
Auto multisport activities Yes Yes Yes
Manual multisport activities Yes Yes Yes
Course guidance Yes Yes Yes
Segments (Live, Garmin) Yes Yes Yes
Strava features (Beacon, live segments) Yes Yes Yes
LiveTrack Yes Yes Yes
Group LiveTrack Yes No Yes
Touch and/or button lock Yes Yes Yes
Hot keys Yes No Yes
Auto scroll Yes Yes Yes
Activity history on watch Yes Yes Yes
Heart Rate Features
HR zones Yes Yes Yes
HR alerts Yes Yes Yes
HR calories Yes Yes Yes
% HR max Yes Yes Yes
% HRR Yes Yes Yes
Recovery time Yes Yes Yes
Auto max HR Yes Yes Yes
HRV stress test (measures your heart rate variability while standing still, for 3 minutes, to provide you with an estimated stress level; the scale of this is 1 to 100; low scores indicate lower stress levels) yes (with compatible accessory) yes (with compatible accessory) yes (with compatible accessory)
Records heart rate while swimming No yes (with HRM-Tri™ or HRM-Swim™) yes (with HRM-Tri™ and HRM-Swim™)
HR Broadcast (broadcasts HR data over ANT+™ to paired devices) Yes Yes Yes
Running Features
Preloaded run profiles Running, Treadmill Running, Indoor Track yes Running, Indoor Running, Trail Running
GPS-based distance, time and pace Yes Yes Yes
Running dynamics (with accessory) Yes Yes Yes
Vertical oscillation and ratio with accessory) Yes Yes Yes
Ground contact time and balance (with accessory) Yes Yes Yes
Stride length with accessory) Yes Yes Yes
Cadence Yes Yes Yes
Performance condition Yes Yes Yes
Lactate threshold (with accessory) Yes Yes Yes
Run workouts Yes Yes Yes
Race predictor Yes Yes Yes
Foot pod capable Yes Yes Yes
Outdoor Recreation Features
Preloaded outdoor recreation profiles Skiing, Snowboarding, XC Skiing, Stand up Paddleboarding, Rowing Hiking, Climbing, Skiing, Snowboarding, XC Skiing, Stand Up Paddleboarding, Rowing, Jumpmaster, Tactical
Point-to-point navigation Yes Yes Yes
Bread crumb trail in real time Yes Yes Yes
Back to start Yes Yes Yes
TracBack® Yes No Yes
UltraTrac mode Yes No Yes
Elevation profile Yes No Yes
Distance to destination Yes Yes Yes
Barometric trend indicator No No Yes
Storm alert No No Yes
Trail run auto climb No No Yes
Vertical speed Yes No Yes
Total ascent/descent Yes No Yes
Compatible with BaseCamp™ Yes No Yes
GPS coordinates Yes Yes Yes
Projected waypoint No No Yes
Sight ‘N Go No No Yes
Area calculation No No yes (via Connect IQ™)
Hunt/fish calendar No No yes (via Connect IQ™)
Sun and moon information No No yes (via Connect IQ™)
Dual grid coordinates No No Yes
Cycling Features
Preloaded cycling profiles Biking, Indoor Biking yes Biking, Indoor Biking, Mountain Biking
Courses Yes Yes Yes
Bike lap and lap maximum power (with power sensor) No Power Yes Yes
Race an activity Yes Yes Yes
Time/distance alerts (triggers alarm when you reach goal) Yes Yes Yes
Interval training Yes Yes Yes
FTP (with accessory) No Yes Yes
Compatible with Vector™ (power meter) No Cycling Power Yes Yes
Power meter compatible (displays power data from compatible third-party ANT+™-enabled power meters) No Cycling Power Yes Yes
Compatible with Varia Vision™ (head-mounted display) Yes Yes Yes
Compatible with Varia™ radar (rear-facing radar) Yes Yes Yes
Compatible with Varia™ lights Yes Yes Yes
Speed and cadence sensor support (with sensor) yes (ANT+® and Bluetooth® Smart) ANT+ Only yes (ANT+® and Bluetooth® Smart sensors)
Swimming Features
Preloaded swim profiles Pool Swimming Pool Swimming, Open Water Swimming Pool Swimming, Open Water Swimming
Pool swim metrics (lengths, distance, pace, stroke count/rate, calories) Yes Yes Yes
Stroke type detection (freestyle, backstroke, breaststroke, butterfly) Yes Yes Yes
Swim efficiency (SWOLF) Yes Yes Yes
Drill logging Yes Yes Yes
Pool swim workouts Yes Yes Yes
Open-water swim metrics (distance, pace, stroke count/rate, stroke distance, calories) No Yes Yes
Heart rate (real-time during rests, interval and session stats during rests, and automatic heart rate download post-swim) No yes (with HRM-Tri™ and HRM-Swim™) yes (with HRM-Tri™ and HRM-Swim™)

 

Fly In The Ointment

 

The 645 is super exciting. However my worry is that it looks a bit too much like the Vivoactive 3. And maybe it is a bit too much like the Vivoactive 3. If so this could be a Houston moment…I hope not.

Read this to see what I mean:

Garmin Vivoactive 3 Review – Detailed | Apple Watch Competitor

 

If you are keen for the most tech awesome running watch right now then it would have to be the Garmin 935 (reviewed here) but, be warned, that the 645 has music and  Garmin Pay

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Source: garmin.com

 

 

48 thoughts on “Garmin Forerunner 645 Specs (Detailed) – Comparison To 735XT and 935

      • Says iHeart Radio. You can download for offline play.

        “iHeartRadio: All Your Favorite Music. All our Favorite Stations

        iHeartRadio has unlimited music and thousands of radio stations all in one app. Sign up for a free trial of iHeartRadio All Access today to take your favorite radio stations, music, news, podcasts, sports, talk and comedy shows offline while you run. Get your 30-day trial here.”

        • I saw the mention of iHeartRadio, though I’d be very disappointed if that’s the only streaming service that can sync with the 645. If that’s indeed the case, I’d personally wait until other services are offered or perhaps pass entirely on the 645.

  1. Great,that’s my present sorted out, delighted they have dropped the touchscreen was one of the main reasons i returned my 630 previously and got a 235 instead. The silver ring out the outside looks a bit like the 405 touchring, hope they are not bringing that back.

    • it’s not 100% yet but that’s how it looks to me.
      we need to just check it’s a bit better than the VA3 before we let you spend your hard-earned cash tho 😉 Please keep Mr Visa at bay for now 🙂

      • May I ask why you don’t like a touchscreen ? I own a 620 and I am so used to touch the screen when I want to switch between data fields. To me, it seems easier when running. I didn’t buy the 935 almost only because of this but maybe I’m wrong.

  2. As a 935 owner I won’t be changing but if I was buying from scratch today then it would be a contender. I’m mostly a runner these days, I do cycle but don’t use a power meter and I don’t swim in any meaningful way. The music feature is something that I want badly but I have fears about how usable the Garmin interface will be (both in terms of getting music onto the device and playing it on the move – I only actually want basic shuffle all functionality while running). And then comes along the big dealbreaker for me (if correct), battery life. Goodbye to charging once a week or less as with my 935. I’ve done the daily (or every other day) charging with an Apple Watch and don’t want to go back to that. Same old Garmin really. I know they need to give a reason for people to buy the expensive devices, but with 5 hour GPS I’d be marginal for completing a marathon before my watch died (I said I run, I didn’t say i was fast!!!). In short, if I was buying then I’d choose the 935 again and continue with my iPod shuffle for a while longer

  3. Wow, that thing is DoA. Other than on-board music (the first in an obvious trend of watches to come with music storage) it doesn’t fit ANY niche at all. biking with no power, swimming with no HR cache, no triathlon…and just 50 bucks cheaper than the vastly superior 935, which is going have a price drop around the launch of the 645…

    I’m sorry for the incoming Hyperbole…but the watch is a Frankenstein monstrosity of a device. It’s almost like Garmin was milling around in their workshop and took all the odds and ends from every other watch they made in the last year, took a bit of glue and duct tape and “VIOLA!”

    You have the 645.

    • It’s as bad as all the other gimmicks at these crazy prices. At least we should praise the fact that is targeted at the disappearing niche of (semi) serious runners and not at the general group of fitness users with disposable income in their pockets who because they wear lycra and sport a $500 watch they see themselves as athletes… LOL

      • hey that’s me you’re describing there 😉
        but yes, i agree with your sentiment.
        my concern is kind of related in that if it’s like the VA3 then it’s not really a sports watch but rather a 247 watch with gret runnign features. the music WILL be really appealing to LOTS of people…probably this products saving grace.

  4. The new 645 watch is not on Garmin’s website anymore. As a runner only, it looks like it has more than I need and all there can be today in a GPS watch. The music and the stronger glass are a big plus and the smaller size will be much better for my small wrist.

      • For runners only this would be a great high-end watch (even at $450) if the battery life is better than listed above. We’ll see. For me (primarily a runner who wants daily activity tracking and notifications), recharging more than once a week doesn’t differentiate much from alternatives (i.e., 935). Perhaps that’s their plan!

        • Battery life for TomTom Runner3 is 5 hours with GPS+HR+music, while 9 hours for GPS+HR only. If that’s the same for the FR645, then it’s acceptable, but far from good for a 450 EUR watch .

          • good point MArc, I was going to double check that same comparison myself.
            so we could probably still see 8-11 hours for the 645 in non-music mode.
            put the gps in ‘worst’ mode
            add a decent footpod
            use a hrm

            and then maybe its even more.

  5. Good timing, a fall at a hill running event at the w/end has left my 620 with a big scrape across its face (& me with a few stitches on my forehead!) so think I know what my xmas present to myself will be 🙂

  6. The big plus it seems is they have finally added a baro altimeter to their top running watch which is a huge plus. To people running up and down a lot that’s very nice also not having to rely to altitude adjustments on the websites. Touch screen on the 630 was good with some head scratchy features (like you cant just block the screen and not the buttons) – could have left it with improvements. Music check… Optical Heart Rate… serious runners will still use chest straps for sessions that matter

  7. I’ve been waiting since june for this release to finally decide which Garmin watch to buy.
    The 935 feels overkill since since I’m predominantly a runner (albeit slowish) but the features listed don’t fully convince.

    Guess I’ll wait for your in-depth review and comparison (wink-wink) before the final decision.

  8. Why is this music feature so desired? You lose battery life and your phone will do it better. Are you not going to carry a phone then when you run? Also, any update on a successor to the 235? I was hoping the 245 would be out by now…Thanks!

    • personally i run with music 0.01% of the time. but i see a LOT of people running with music. say 50%.

      245..nope nothng. it’s one of those ‘obivous’ things that will happen. obvious apart from the timing. but it will be no later than q1.2018 i reckon

      • Right I am not saying people don’t run with music – but why would you want a dumbed down version of music on your watch when you have your phone that has everything? Do people not carry a phone when they run? Bah – I was holding out for a running watch instead of buying the 235. The 935 seems like overkill for me and this 645 has music which I don’t want/need. Do you have any info on what the 245 would have? Thanks!

        • saves 2 devices. garmin will have done market research.
          when i have to carry a smartphoen to handle some bizarre sensor it is a real PITA..i really dont like carrying a phone.
          why dumbed down? quality will be the same if you think about it
          you are a 245 man i reckon

          • Yes just don’t want to sacrifice battery for music. But in any case, do you have any info on what to expect from the 245?

          • no info. but look at the other post compareing 235/630 and 645 and then you can extrapolate what will be taken out of the 645 to make the 245. I might do that as a post but I am running out of time as I have to make a honest living elsewhere!!

    • I run with music about 95% of the time, so a watch with music storage does appeal to me. I currently carry a phone for the sole purpose of music, it would be nice to carry one fewer device. It’s likely that I fit squarely into the “semi-serious runner” market segment that Garmin is targeting with the 645.

    • Call me crazy but I do not want to carry a 6 inch phone with case and a magnetic plate under the case(for easier hookup in the car) every time I run. I just want to run free…but with music. 😉

    • I assume most people would prefer to run without a phone if possible. I do. What this is missing is some sort of LTE capability for emergency access, like the Apple Watch. Otherwise, it’d be a home run.

    • 90% chance i’d say
      OR garmin could rationalise that they have the price right for the 645 compared to the range and so no need to go to the expense of making, packaging and selling a another variant.

  9. if SANS music the battery is up in the 15 hour range, and the BARO gives a reasonable vert reading, I’ll be there. Otherwise, I’m hopping over to the Suunto Spartan range…

  10. You have ‘type-o’ in the title. 745XT… I wish I had… 🙂
    Nevertheless I think that 645 is watch I was looking for BUT… with so weak battery and for so much money I would again consider choosing 935 over 645. BUT (again 🙂 I bought 3 weeks ago with a big discount the 735XT run Bundle version for 320 Euros and the price performance ratio is the best what I could “squeeze” from it.

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