The app incorrectly measures a half marathon as 20 KM instead of 21.1 KM.
Ultra 2. The watch correctly measures distance, but the app incorrectly defines a (metric) half marathon as 20 kilometers. The correct distance is 21.0975 kilometers. The error is software side, not hardware.
Ultra 2. The watch correctly measures distance, but the app incorrectly defines a (metric) half marathon as 20 kilometers. The correct distance is 21.0975 kilometers. The error is software side, not hardware.
Which Apple Watch do you use?
Did you already calibrate your watch?
Calibrate your Apple Watch for improved Workout and Activity accuracy - Apple Support
If you are using the default Apple Workout App, did you try to use a 3rd party app, for example WorkOutDoors, to compare the results?
In case only the Apple Workout App shows this error, you should let Apple know about the issue by using the Feedback link. This is the only way to reach them directly.
Fitness App incorrectly measures Half Marathon
