A comparison of 3 different devices to try determine which is the more accurate with regards to recorded elevation gain. I found one better than the others on this particular short route. However with proper calibration, Garmin devices using a barometric altimeter generally report elevation with a margin of error of \(+/-10\) feet to \(+/-50\) feet (\(3\) to \(15\) meters). The accuracy can vary based on weather conditions and how recently the device was calibrated. Any margin of error I imagine would be greatly magnified the longer the length of the route.
