The percent grade between elevations is a term often used in bicycling to determine how steep a fill is. The percent grade formula takes into account rise and run. Run is the horizontal distance between the two points you are using to find the change in elevation. It is important to remember, however, that the run does not equal distance traveled; run is the distance between the two points as the crow flies. Using distance traveled will result in incorrect calculations.
Measure on a map the distance between the two points you want to find the percent grade to find the run. For example, assume it is two miles.
Determine the change in elevation between the two points to find the rise. This is elevation at point 2 minus elevation at point 1. In the example, assume the change in elevation is 0.5 miles.
Divide the rise by the run. In the example, 0.5 miles divided by two miles equals 0.25 or a 25 percent grade.