Why do the kilometer totals differ on the blaze and the fitbit app?

[thighmaster]

When I start my run, I started the exercise/run on my Blaze. Then I started the exercise tab on the iphone fitbit app. The blaze says 4 K while the app says I ran 5K. The picture shows the results. How do I recalibrate so they will be the same. 

Thanks

[MikeF]

The bigger question is probably 'Why are you using two different tracking methods to track a single exercise?'

You can't callibrate anything here (if the Blaze was using GPS as well as the app) and given that the two methods of tracking the run are effectively mutually exclusive and not meant to be used together, most people wouldn't even be aware of a difference.

If the Blaze was simply counting steps and not using GPS then I can understand why you were using both options and that is a recognised way of using the technology for trackers without GPS but since the Blaze is capable of using the phone GPS for itself, I would still propose that this would be a better way of tracking things. Regardless of all that, however, setting a more accurate stride length will go some way towards addressing the difference.

[thighmaster]

Thanks for the reply Mike, I am running indoors on a track. The GPS is not functioning as the phone has no sim card(wi-fi only). I was assuming that the iphone app was using the blaze step counter is that not the case? After further research I've learned that I actually ran 4.5 k (according to the track length and number of laps run) instead of the 4k or 5 k. It appears I will need to determine stride lengths for better accuracy.