GPS accuracy during exercise

[wrebble]

Picture says more than thousand words so... picture first.

How can it be that the same lap is measured THAT wrong. It is 1,27 km difference which is BAD. Both lines run on the same road so it can not be just "difference". Step count is the same and also the time. Which one can I trust at all? It isn't the first time it has happened (at least once more). 

FitBit app is up to date. My Versa 2 is up to date.

I started my run the same way: opened exercise - choose "run" - wait FitBit to connect with "connected GPS" - start!

Also the settings are the same when I start the run. I activate "do not disturb" and "always on display".

Am I doing something wrong? Is the app so bad that it does not know how to calculate distance? Is it problem with my watch? I looked into it and it seems this problem has been with you for 3.5 years. Is there seriously no fix?

Anyways, I posted this in "App" section because it seems to be problem with an app. If not let me know.

Moderator edit: Subject for clarity 

[Vik123]

my GPS for my last three runs has been nearly a mile under.  I have tracked these on Google maps and my route for 7 miles is under.  This has now happened over my last three runs where the route has been under by nearly a mile.  My versa was working fine but over the last 4 days is out.  These two runs are the same route.  I am currently raising money for charity by running 100 miles in June.  I feel completely let down by my versa 2 at present. my pace is also completely out.   I have reset/unpaired etc but still not working.

[SunsetRunner]

I followed the instructions, used reset, turned off the "set automatic", sync'd the fitbit.  We went for a walk today and when we came back I checked the settings and they changed from -- to the normal stride distance.

[M3tr1c]

It may end up changing back to putting numbers after the workout you do. I have to reset it and sync every time I go for a run otherwise the watch keeps those lengths and my run is way off. 

[eepyaich]

While this whole "stride length" thing might help under some circumstances, the fact people are seeing similar inaccuracies on bike rides implies there's something more fundamental going on, I fear!

[wrebble]

@M3tr1c You promised us some info if your distances are correct now. Are they? 🙂

@eepyaich Well I've recorded two 40km bike rides with my watch. One was 200m less than actual and other 400m. Had some connectivity issues during ride. What I do not understand is that Strava recalculation uses the same coordinates / path to calculate the distance and somehow still they are different from Fitbit ¯\_(ツ)_/¯

[Jbp1954]

I've been tracking my Fitbit distance vs. my mechanical bike computer for a few months now. The Fitbit is all over the map.

For my last 6 rides, I've added in the data from my Samsung Health app. I have a Samsung Galaxy S10+ phone. I had the same issues, though, with my previous phone, a Galaxy S7.

What I'm finding is that, for the last 6 bike rides, the Samsung health readings are consistently 97% of the mechanical bike computer, which means I can probably calibrate the wheel diameter variable in the computer slightly, as I believe the Samsung Health GPS/Distance readings are probably correct.

The Fitbit numbers, though, are still all over the place. My last four rides have been 6 miles on the computer, and all have been 5.8 miles on Samsung Health. 

But on the Fitbit, they've been 6.16, 6.21, and 5.89. Same route with very minor variation.

I've sent all the data to Fitbit numerous times, including phone and OS data/ID, yet, all they do is come back and ask for it again. It does not seem they're really doing anything....

Here is the chart for the last 6 rides. The column Fitbit/Computer is simply dividing the Fitbit number by the computer number to create a ratio. Ditto for Samsung/Computer:

Distance (Computer)	Distance (Fitbit)	Fitbit / Computer	Samsung Health	Samsung / Computer
3.71	4.16	1.12	3.59	0.97
5.14	5.02	0.98	4.99	0.97
6.00	6.16	1.03	5.86	0.98
6.00	6.21	1.04	5.80	0.97
6.00	6.21	1.04	5.80	0.97
6.02	5.89	0.98	5.83	0.97

Here is the chart showing the data for several months - you can see the variation in the Fitbit data is VERY large:

Distance (Computer)	Distance (Fitbit)	Fitbit / Computer	Samsung Health	Samsung / Computer
6.22	5.64	0.91
6.40	5.90	0.92
5.30	4.22	0.80
7.57	6.78	0.90
5.60	5.45	0.97
6.01	5.98	1.00
4.39	3.82	0.87
4.41	4.14	0.94
4.40		0.00
4.60	3.93	0.85
7.52	6.74	0.90
4.71	4.85	1.03
7.57	9.14	1.21
1.07	1.15	1.07
5.25	5.47	1.04
4.05	4.09	1.01
5.40	4.69	0.87
6.33	3.47	0.55
6.00	5.50	0.92
6.10	5.83	0.96
6.18		0.00
5.20	4.94	0.95
7.70	7.98	1.04
2.85		0.00
5.85	5.38	0.92
3.95	3.45	0.87
5.15	4.63	0.90
4.11	3.77	0.92
4.51	4.66	1.03
5.51	5.47	0.99
3.89	4.04	1.04
5.85	6.84	1.17
4.15	3.40	0.82
6.32	6.34	1.00	6.13	0.97
3.71	4.16	1.12	3.59	0.97
5.14	5.02	0.98	4.99	0.97
6.00	6.16	1.03	5.86	0.98
6.00	6.21	1.04	5.80	0.97
6.00	6.21	1.04	5.80	0.97
6.02	5.89	0.98	5.83	0.97

[M3tr1c]

@wrebble So far it's actually been accurate for my runs. Though I've still had to clear my stride info every time. Not sure what would happen if I didn't but doubt it'll work. 

Haven't heard anyone say it's worked for them yet so I was giving it some time before I told people. 

Sorry I can help you cyclists. Wish we would hear from the mods about an update or something. 

[Tjj707]

About a week ago I decided to test out using my work iPhone7 after the post from wayneramp.  After a week of morning runs I confirmed the very close results from my Android running Endomondo and Fitbit Versa 2 using connected GPS to the iPhone7.  With runs between 6-7km the maximum difference between the two devices was .07km over a 7km run.  Today's run produced almost identical final result and every 1k split was within 15m or so.

While this is not a fix, it seems to confirm the issue is not with the watch or settings within the app but with the Android Fitbit app itself.  So if you have access to an iPhone it could be workaround but really Fitbit needs to fix the Android app.

[Vik123]

Given up and bought a Garmin...which to be honest has much more detail in the app.  I have had a Fitbit since they first arrived and wasn't sure about switching but took the plunge. 

[tecishere]

@Tjj707  Not the case im afraid. I was using iPhone 7 and had exactly teh same issues as being experienced with Android phones. It was OK for a long time but once it got the bug that was it. Switched to Apple Watch 2 and havent looked back.

[busterandwoody]

I have also given up and bought a Garmin after being with Fitbit since 2015..love it!! Accurate runs at last!!! 

[SammyP123]

I can't stress enough to people...ditch FitBit...get a Garmin. Vivoactive 3 is cheaper than a Versa 2...absolutely brilliant and well worth the money. 

[Vik123]

Yep bought the vivoactive 4s love so much more features. 

[M3tr1c]

Guh....the return date for my versa just passed...I went for a run yesterday but ended up with the distance short of about half a mile. Ive been thinking of getting a Venu but I really wish we would get an update on this. If I end up working a bit more I may jump ship also... 😞

[wayneramp]

I have now run the same course with iPhone and Android with a group of
runners(Garmin users) when paired to iPhone the descepency is under .25 of
a mile for a 10 mile trail run. I twice ran with both phones. Each time I
paired the watch to a different device. When the watch was paired to the
Android the result were off by a mile(under).

I am now running with iphone paired to versa. On one run I saw the watch
lose connection to the phon3 mid run for about a half mile. It reconnect
and distance was not off at the end.

[wrebble]

Okay so I tried to do as @M3tr1c did. I turned off "auto recognition" and zeroed my stride lengths (--cm). The real distance was 8.3 km but Fitbit still somehow managed to get 11.12 km (+ 2.82 km).

I mean, I'm flattered that Fitbit thinks that I'm fit and fast but I do hate lying. I would like someone to be real with me and motivate me to do better, not the other way around.

@MarreFitbit Any news? Or should I ditch my Versa 2?

[SunsetRunner]

@wrebble Was your last post deleted by any chance? Same thing happened to me. Thought it was a free country!! Apparently Fitbit don't think so 😂

[wrebble]

@SunsetRunner Yep, because "we don't allow discussion of legal action against Fitbit on the Community". This kind of issue they can resolve within 12h but semicolon issue in code takes over 8 months.

I mean, how hard is it to take the code from October 2019 update and the one before that and then compare what went wrong.

[SunsetRunner]

Thought so. Mine got deleted for the same reason. I said I was going to inform BBC's Watchdog programme about the whole story, which I have done. I can't see that that is legal action though! These posts will probably get deleted soon I'm sure 🙂

[wrebble]

Well mine was about "legal action" for sure. I find that something has to be done, legally or not, so that we could push them to fixing this. This is stupid how long does it take to fix this.

(Yup, this post will get deleted for sure)