Same walk 2 fitbits - different distances (GPS on)

[dml5064]

My wife and I went one a walk and both used the "walk" exercise with GPS on. The maps are the same but hers is less. Measuring on Google maps shows mine is accurate and hers isn't. Why is this? The GPS seems right, but distance is off!

[Rufous44]

Because Fitbit measure distance via steps and not via GPS.

[James291]

We see discrepancies between our two Versa 3 watches. Over a 5 km GPS tracked run, our distances regularly vary between 0.05 km and 0.15 km. I assumed it was partly due to GPS inaccuracy and partly due to Versa 3 'limitations', but now I'm not sure. I can see in the exercise settings that running stride length is automatically set by GPS and other stride length is manual, but I assumed this was only used for non GPS exercise.

@Rufous44 GPS tracked exercise distance is calculated from steps? Is this confirmed by Fitbit or something worked out by the community?

@dml5064 Can you tell us how far the walk was and what was the length of the discrepancy?

[dml5064]

2.8 miles. Wife was 1.5. Steps were the same. Her pace was rated as much slower. 

[dml5064]

I thought that is the whole point of having gps...

[James291]

@dml5064 That discrepancy is quite large, is this a one off or regular?

I've had one instance when my Versa 3 got the distance/pace badly wrong. I restarted it and it hasn't happened since.

[vee]

I posted last week that my Versa 3 distance was lower than other devices. (but not as much as your wife's! Just consistently a bit low, and yes it therefore gives a false slower pace)  Fitbit says they use GPS distance, but user experience is different!  Cannot get a straight answer from Fitbit!  No one from Fitbit replied to my query though I quoted them from another recent thread that GPS is used.  Most users think steps are used.   I thought my steps were ok, but they should have given me a longer distance. It is annoying. 

[dml5064]

It's been a while since we did something together. In the past it's usually closer but rarely the same. Even with GPS. This was just exceptionally egregious. 

[dml5064]

There are many inaccuracies with Fitbit. I also have the floor glitch which routinely tells me I hiked up the empire state building. 

[vee]

If it's windy you'll get extra floors. It is measured by barometric changes. In my usual daily routine it undercounts my floors. 

Despite the glitches I still really like Fitbits. All in all it's pretty accurate. 

[Rufous44]

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@Rufous44 GPS tracked exercise distance is calculated from steps? Is this confirmed by Fitbit or something worked out by the community?

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Fitbit states the contrary but it is evident they never bothered to check by themselves. Try to start a running session while driving or biking, you will see a distance nearly zero(because of some steps are anyway detected due to vibrations) even after few kilometers.

[Rufous44]

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@vee wrote:

If it's windy you'll get extra floors. It is measured by barometric changes. In my usual daily routine it undercounts my floors. 

Despite the glitches I still really like Fitbits. All in all it's pretty accurate. 

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My wife's Sense yesterday measured 35 floors staying home all day (according to her she went upstairs twice). And I can assure windows were closed so it wasn't windy.

[vee]

It doesn't matter if the windows are closed! Was it windy outside? It's the barometric pressure. 

[vee]

Anyway, I guess we agree that the floor counting is fairly useless. It used to be better. My Versas have been terrible, missing my usual floors that the Charges counted. 

[dml5064]

I will have hundreds of flights and my wife will have several. We live on the first floor, no stairs. Its not the wind...

[Smstext]

Same up to 20% difference on 5k parkruns to other devices showing I've actually run 4.5km on an officially measured route and other devices are showing 4.99 up to 5.2km.  have full GPS, no cover or huge buildings to interfere and Strava will record the run to within metres.

[Rufous44]

@Smstext 

When you say that Strava measured the right distance was that distance shown from a session measured via Strava app running on your phone or from the Fitbit run synced to Strava?