Runkeeper miles walked not matching with Fitbit

[jen_nah]

I just bought a Fitbit Flex yesterday. Today I did my 1st work out with the Flex. I have been using the Runkeeper app on my iPhone for years now and it gives me my miles walked, etc... When I check Runkeeper it states I walked 4.75miles today but my Flex is only showing 3 miles. Runkeeper is accurate as it uses GPS tracking. How do I manually change this on my Flex dashboard?

Thanks,

Jenny- Fitbit Flex newbie

Moderator edit: updated subject for clarity

[SteveH]

Your fitbit calculates distance by simply multiplying the number of steps it registered by your stride length. If the miles are coming up short then either it is missing some steps or the stride length used is too short.

There's not a lot you can do about the steps as long as you are wearing it correctly and, assuming it's on your wrist, that your arms are moving normally. You can always do a test by counting out, say, 100 steps and seeing what your Flex reports. This article discusses the accuracy of the Flex:

https://help.fitbit.com/customer/portal/articles/1140292-how-accurate-is-my-flex-

Regarding the stride length. Fitbit uses 2: one for walking and one for running, and uses defaults based on your profile settings (mainly gender and height) so it's worth checking that your profile is set up correctly. If you want, you can override the defaults. They can be found at: https://www.fitbit.com/user/profile/edit (note that they show as zero if the defaults are in use).

This help article describes how to measure your stride:

https://help.fitbit.com/customer/portal/articles/176045