What is the correct formula to determine the percent slope of a ramp?

To determine the percent slope of a ramp, the correct formula is to use the rise over run method. This involves measuring the vertical height that the ramp rises (the rise) and the horizontal distance it covers (the run). The slope percentage is then calculated by dividing the rise by the run and multiplying by 100 to express it as a percentage.

For example, if a ramp rises 2 feet over a horizontal distance of 10 feet, you would perform the calculation as follows:

[ \text{Percent Slope} = \left(\frac{\text{Rise}}{\text{Run}}\right) \times 100 = \left(\frac{2}{10}\right) \times 100 = 20% ]

This calculation provides a clear understanding of how steep the ramp is relative to the horizontal distance it covers, which is critical for assessing usability, especially for accessibility standards. The rise indicates how much the ramp elevates, while the run shows the length over which that elevation occurs. This method directly aligns with industry practices for evaluating ramps in terms of their safety and accessibility.

In contrast, the other options do not accurately reflect the correct relationship necessary for calculating the percent slope. For instance, height over distance may suggest