How does Versa calculate walk/run distance?

[sn2019]

I took a walk today with my Versa tracking my route with GPS data from my Samsung S10+. For the same walk, I also track it with Mapmyrun app on my phone. Since my phone is providing GPS info, my Versa and Mapmyrun should show the same walk distance, shouldn't they? According to Mapmyrun, I walked 2.29 miles in 39 minutes 34 seconds. According to my Versa, I walked 2.68 miles in 39 minutes 34 seconds. According to Fitbit, it took me 5,022 steps to do the 2.68 miles. If I multiple my stride length by 5022, I don't get 2.68 miles. If I multiple 5022 by 30 in (Fitbit's default stride length for male), I don't get 2.68 miles.. If I multiple 5022 by 26 in ( Fitbit's default stride length for female), it is not 2.68 miles. So the question is how did Versa/fitibit dashboard came up with 2.68 miles???

Couple other points:

- When I exported the TCX file to Google earth, I don't see any disconnection of GPS between my phone and Versa.

- This is not the first time this happen.

- If I track my walk from the Fitbit app on my phone, my walk distance is very close to Mapmyrun.

[JohnnyRow]

See How does my Fitbit device calculate distance traveled? 

Stride length is used only when you are not using GPS.

[sn2019]

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@JohnnyRow wrote:

See How does my Fitbit device calculate distance traveled? 

Stride length is used only when you are not using GPS.

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Fair enough. I didn't press "start" until I see the "connected" message on my Versa. If it was connected to my phone's GPS during my walk, shouldn't the distance more or less the same as Mapmyrun?

[sn2019]

I did another walk today (that I tracked). According to Fitbit app on my phone, I walked 3.7 miles. I exported the walk to an TCX file and imported it to GPS Track Editor (http://www.gpstrackeditor.com/ ). The GPS Track Editor said my route is only 3.2 miles long. Wonder why they are not the same if the GPS data are the same?

I also imported the TCX file to http://www.mygpsfiles.com/app/ and it agrees with GPS Track Editor.

Before this walk, I have uninstalled/reinstalled Fitbit app on my phone as well as reset my Versa.

[sn2019]

For this morning's walk (2/16), I have my Versa on but tracked my walk from the Fitbit app on my phone as well as MapMyRun from my phone. After the walk, Fitbit said the walk is 4.13 miles and MYR has 4.2 miles. The difference can be attributed to I started MYR before Fitbit.

[sn2019]

Did a short little experiment... I set my stride length to 100 in, tracked my walk from my Versa after it is connected to my phone and also tracked my walk with MapMyRun on my phone. An 0.28 miles walk shows up as 0.34 Mi on my dashboard, while MYR has it at 0.28 Mi. Export the TCX file from FB to GPS track editor and it shows the walk is 0.28 MI.

FB step count for the walk is 650 and MYR step count is 632. With my stride length set to 100, it is obvious step count and stride length is not use to calculate the walked distance.