Select your product to confirm this information applies to you
Inaccurate Elevation on the Forerunner 910XT or Forerunner 920XT
The Forerunner 910XT and Forerunner 920XT have built-in barometric altimeters that are used to determine the elevation during activities. An issue can occur with the barometric altimeter where there is a substantial difference between the value shown on the watch and the actual elevation.
There are several troubleshooting recommendations that can help to ensure the device is recording accurate elevation. Troubleshooting suggestions include:
Calibrating the Forerunner 910XT barometric altimeter to a known location (see Calibrating the Altimeter on My Forerunner 910XT). The 920 does not offer a calibration option.
Ensure the device software is up to date using Garmin Express.
Rinse the barometer port with fresh water and allow it to air dry.
Forerunner 910XT: The barometric altimeter port is located on the back of the watch near the bottom right charging contact.
Forerunner 920XT: The barometric altimeter port is located on the front of the device in between the Back and Enter buttons.
If the above troubleshooting steps do not provide accurate elevation data, or your device is reporting an elevation that is off by 10,000 feet or more then it is possible that the barometric altimeter on your device has failed.