Distance accuracy between Charge 3 and MapMyRun

[Melissa.96]

I went for a run today and had different distance results on both apps (both using GPS).

My charge 3 said I ran 3.42 miles whereas Map My Run said I ran 3.14 miles. This is a big difference and made my pace results very different (10’38’’ vs. 11’32’’).
Which is more accurate? Which should I use going forward?

Moderator edit: updated subject for clarity

[MarreFitbit · Accepted solution]

Hello @Melissa.96, welcome to the Community Forums. We're sorry for the late response, due to recent events affecting our operations, we're taking longer to respond.

Thanks for the details provided about the distance accuracy of your Charge 3 and for taking the time to compare it with MapMyRun. 

While reading your post I was wondering if the mobile device you're syncing with is included in our list of supported devices? You can see the list at: Which phones and tablets can I use with my Fitbit watch or tracker?

Fitbit products are compatible with most devices that have the following operating systems: Apple iOS 12.2 and higher, Android OS 7.0 and higher, or Windows 10 v1607 or higher. 

Please keep in mind that when a device is not supported and does not meet the require OS we cannot guarantee its functionality with the Fitbit app. It might work at a certain time and then it can stop working out of nowhere after an update. This is because the app is not optimized to that device and any change could impact the performance. 

Fitbit devices calculate distance by multiplying your walking steps by your walking stride length and multiplying your running steps by your running stride length. We estimate your stride lengths using your height and sex. Track one or more runs using on-board or connected GPS, we evaluate that data to automatically update your running stride length. For best results, run at a comfortable pace for at least 10 minutes.

If you prefer to measure your walking and running stride lengths yourself and enter them manually, see Can I change my stride length in my Fitbit account?

Note that when you're tracking an activity with GPS, Fitbit calculates your distance using GPS data rather than steps. If you begin moving before you get a GPS signal, the tracker will calculate distance using steps and stride length as described above until a GPS signal is found.

Keep in mind that your device uses your step count to calculate distance until it finds a GPS signal. In this scenario, your total distance calculated for the workout may be slightly less accurate than if GPS data were available for the entire duration. For more information, see How accurate is my GPS data captured by my Fitbit device?

After reviewing this factors, please go for another activity and see if the distance improves.