Step tracking accuracy

[Ravenlake]

My girlfriend, 5'10" and I , 6'1", each have new fitbits. Hers registers substantially more steps than mine. We have double checked our setttings and do not understand why this is happening. Example: we walked everywhere together today, except I walked a 3100 step walk without her at the beginning of the day. Just now we compared and hers says 8233 steps and mine says only 8140 steps. This seems a very large discrepancy to me and I'd like to know what is causing it. 

[MarcoGFitbit]

Hello @Ravenlake, welcome!, it's always nice to greet new members in the Community!

When you set up a Fitbit tracker, you're asked to fill some personal information such as height, weight, age and gender, this way every Fitbit tracker gets personalized and will track accurately each person's steps, calories, distance and such.

The discrepancy you're seeing between your girlfriend's tracker and yours is because the tracker is basing its data on each of your BMR's, as she's shorter than you, her Stride Lenght is shorter, therefore, the step count will increase. If you want to know more about stride lenght, please refer to this article, I'm sure it will very helpful for you. 

I hope this information can be helpful, feel free to reply in case you need anything else!