Charge 4 isn't tracking my distance accurately

[PSHEPLER7]

Hello, 

Recently ran a 1/2 marathon. My running partner wears a Garmin and I have a Charge 4. At the end hers registered 13.1 miles as it it should. My Charge 4 showed 12.7 miles. Is there a way to fix the accuracy?

Moderator Edit: Clarified subject

[MarreFitbit · Accepted solution]

Hi there, @PSHEPLER7. Welcome to the Fitbit Community Forums. Thanks for the details provided in your post about the inconvenience with your Charge 4.

As a first approach, I would like to clarify that it's normal that you see a difference when you are comparing your data with another person, this is because Fitbit devices record your data based on your personal information (age, gender, weight and height). 

Fitbit devices use the formula below to calculate distance. Your stride length is determined by your height and sex. Steps x Stride Length = Distance Traveled

Please note when you track an activity with GPS, your device calculates your distance using GPS data rather than steps. If you begin moving before you get a GPS signal, your device calculates distance using your steps until GPS connects.

To update your stride length, track a run with GPS or measure your stride length manually. For more information, see Can I change my stride length in my Fitbit account?

For more information about GPS, see How do I use GPS on my Fitbit device?