Versa not accurate for distance running

[jenniferfink80]

I ran a 10k last Saturday & my Versa said that I ran 7.1 miles, not 6.2.  Does the Versa use my phone's GPS to calculate distance, or stride length?

I am training for a half marathon, so accurate distance is very important to me.

Moderator edit: subject for clarity

[LiliyaFitbit]

Welcome to the Fitbit Community, @jenniferfink80.

I am glad to assist you with your concern regarding your Fitbit Versa tracking the distance correctly. Thank you for providing the additional details. I understand that accurate tracking is important for you and would like to confirm how do you track your exercise? Do you use the Exercise app or let your watch to automatically track your activity? 

Fitbit devices calculate distance by multiplying your walking steps and walking stride length. Similarly, your running steps are multiplied by your running stride length. This will not necessarily match a pre-measured distance, nor will it show exactly what a GPS device will show. Since we use height to estimate your walking and running stride lengths, you may want to measure and manually adjust these values if your legs are longer or shorter than average. For more information, see How do I measure and adjust stride length for my Fitbit device?

If you feel that your distance is inaccurate, confirm the following are correct in the Fitbit app:

• Your wrist settings (For more information, see Does the wrist I wear my device on affect accuracy?)
• Your height (For more information, see How do I manage my Fitbit profile?)

I'll be around.