Hikers of Iredell Club uses a difficulty rating model that calculates a linear total mileage by adding ascension to the total distance. A one mile walk around a flat track would have a difficulty rating of 1.00. Ascent is converted to distance at a rate of five miles per thousand foot. The rate is arbitrary, so long as the rate is consistently applied in a comparison table.
The same one mile walk, adding a 100' hill, would have a difficulty rating of 1.5, or an equivalency of 1.5 miles of distance. (100 * 0.005) + 1.00.
Other entities utilize the same methodology, noting a rate of four miles per thousand, or two miles per thousand. The lower the rate, the lower the rating. The rate of file miles per thousand was selected because it biases the index higher, and sets expectations for a more difficult hike.
The club would rather prepare the hikers for more than they can handle, and surprise to the downside, than vice versa.
|1 mile Track||1.00||0'||1.00|