Charge 3 GPS information not accurate

[Harkin]

Greetings, I am having problems with my GPS tracking on run exercises initiated on my tracker. I run about the same distance on the same path every time. Actually distance is 3.11 miles (or 5K). In the past 3 runs, it has logged it as 2.5 miles, 3.1 miles, and 3.8 miles. This is a huge variance. The maps tracked  on the Fitbit app are almost the exact same. Please help provide troubleshooting steps or ways to make more accurate. I can provide picture proof if needed.

Moderator Edit: Clarified subject

[AlejandraFitbit]

Welcome to the Community, @Harkin.

Fitbit devices calculate distance based on the device’s accelerometer data and stride length setting.

Default stride length is based on your height and gender. If available, Fitbit devices use GPS data to calculate more precise distances.When you sync your device, our algorithm interprets the data from the device, and you see your distance traveled in the Fitbit app. 

Note that when you track an exercise with GPS, both GPS and accelerometer data are used to calculate the distance shown in the Fitbit app. For more information about accuracy, check the article: How accurate are Fitbit devices?.

Let me know the outcome.