I went for a local walk and tracked it on my FitBit Charge 4 and at the same time on my Garmin Etrex20. The FitBit displayed 4.68 miles on the display. The Etrex21 gave 4.1 approx. So I then exported both tracks from the Fitbit in TCX and the Garmin in GPX Using Garmin Basecamp I converted the Fitbit to GPX track. Then used my map package OMN to track them on the map. The 2 distances from the tracks on the mapping app were 4.13 and 4.21 which isn't bad. But is seems to me at the end of the walking excercise what is displayed is not accurate against what the Fitbit has actually tracked from the GPS. I notice others have commented on the inaccurate tracking.
