Fitbits Stats vrs Strava stats from Mobile Phone

[SteveCartwright]

Anyone know why there is always less KM completed via Fitbit to Strava, also KMPH , which is more accurate ? I run the Charge 4 Fitbit

Moderator edit: format. 

[Giampi71 · Accepted solution]

This is very common and the explanation is quite easy (as found out by the community).

All Fitbit trackers, regardless the presence of dedicated GPS sensor, measure the distance not via GPS but via a steps multiplied by stride calculation with the stride estimated (somehow...) via GPS. The result is that if your stride is variable (and this can happen quite easily as the stride strongly depends on multiple factors) the distance can be easily wrong, we speak even about 10-20%.

Practically the GPS is used only todraw your trace on the map.

When instead you sync your Charge 4 to Strava, Strava receives the GPS data hence calculate the distance and apply further corrections (general consensus is that Strava own correction algorithm is not much precise). The result is that the 2 data, as you found out, can be sensibly different.

For this reason my general advise, if you are a runner, is to use a different brand because evidently Fitbit is not interested to change its algorithm (present since the release of Ionic).

[Rich_Laue]

I would check and adjust the fitbit stride setting. 

Fitbit says they use both stride and gps to determine distance. 

Strava only gets the GPS data to work with. 

So which is more accurate? Try one of the Google pedometer. Or this one. 

Once I set my stride correctly, my fitbit distance got very close.