Fitbit Charge 5.... Built in GPS.

[Kernow55]

The built in GPS on my Charge 5 is overestimating my walks by approx. 25%. If I walk 4 miles it records as just over 5 miles. Any ideas how to correct this ?

[Guitarplayer · Accepted solution]

Yes, as crazy it sound Fitbit (all fitbits) dont use GPS to measure distance but only to draw the track. Distance (and speed) is measured multipling steps by stride. It seem that stride is somehow evalauted with gps but users agree that this solution is not good as stride can change a lot during the same walk. Mods will tell you to set manualy the stride but this defeat the purpose of having gps.

In your case the stride is overstimated so you should set it at around 80% of what it is.

[Kernow55]

Thanks for the helpful reply. I have already shortened my stride length (on the app.) to below what I think is the true length but I'll try shortening it further.
I had assumed that the Fitbit would work in a similar way to the Garmin I use on my bike when cycling, and would record track and distance together !

[Guitarplayer]

Right, I forgot to mention that for biking Fitbit correctly estimated the distance using GPS (because there are no steps). The community asked since for good to use the same process also for walk/run but Fitbit is ignoring the comments.

[Kernow55]

I cut my stride length drastically and walked without GPS but measured distance on Google Earth when I got home. I was still shown as walking 2.9 miles on Fitbit while GE showed 2.5 miles. I can only assume that because my walking in Devon, UK. entails constantly walking up and down hills and over moorland, my stride length can be so variable that it is difficult to estimate accurately. Maybe it's a problem that I just have to live with.

[Darksheep]

Thats insane... So the watch has a GPS system, but refuses to use it during running? 

So I gave my mother a Charge 5 as a present, and she noticed her 5K runnings were not accurately measured. She returned it to me, and I did a test run. In my tests (comparing a Charge 5 to a Garmin Forerunner 745) it was not that far off. But if it is stride that is measured, maybe with tuning it down it will be more realistic for her. Ill give it a go and report back. 

[EdR01]

Thanks Guitarplayer, this was driving me a bit mad trying to understand why a few walks I took on a known repeatable 4km track were showing as over 5km in the fitbit app. I was using a charge 5 configured to use the built in gps, and like most users figured it would rely solely on GPS data to measure distance for walks and runs (and time for pacing). To echo Darksheep's comment about this quirk, that's insane.

To make matters all the more confusing, cut corners and straight lines between occasional dropped and required gps signals visible on the fitbit map meant my distance would be expected to measure less than its actual 4km, particularly given what the map was visually displaying about my tracked route! That's a significant discrepancy between visually displayed data, fitbit "calculated" data, and the actual route itself. It serves no one to serve up such an obfuscated confused mess.

Its astonishing that this has not been addressed given the time of your reply in 2021, and also that Fitbit make no effort to be transparent on either the charge 5 GPS limitations, or of the fitbit apps distance measurements for walks/runs being corrupted by stride/step calculations. All other forum posts querying spotty GPS and distance inaccuracy issues have received canned moderator responses to 'adjust how you wear the watch when you want to use GPS' or to reset and refer to a generic help page, with the real clue buried in one of the bullet point detailing to wear it one notch looser - hinting to the real cause being the antenna is affected if you wear it too tight. How many users ignore that bullet point because it is: a.) superficially incredulous that wearing it ever so slightly looser should have any meaningful bearing whatsoever on gps - especially if they have used other gps trackers; and b.) are aware that loosening is likely to affect heart rate accuracy - again from any experience with other trackers - and will be less inclined to actually try this. It feels somewhat insulting to all the users bumping up against these same issues.

One user received a response (from another user not a mod admittedly) querying whether he was sure that the several 1 mile markers placed along his route where actually correct... which goes to show the lack of clarity on Fitbit's part about all this.

Next time I will use the bike exercise to track my walks/runs, wear it loose, and which hopefully resolves the gps distance inaccuracy.