I understand the general principle, I am wondering if there is a standard for the Run used by various mapping programs.

For instance there is one hill nearby that I have measured a grade of around 15-16% that shows up with a maximum Grade of 8.1% on Ride With GPS. Then there is another one that they rated at 12.4% which is considerably less steep than the they are calling 8.1%. The really steep hills around here tend to be fairly short, over maybe 100-300', so I suspect that they are measuring a "moving average" over maybe 500'?

Just curious...