Enter the rise and run into the calculator to determine the reverse slope. This calculator can also evaluate any of the variables given the others are known.

Reverse Slope Formula

The following formula is used to calculate the reverse slope.

S = (R / Ru) * 100


  • S is the slope (%)
  • R is the rise (units)
  • Ru is the run (units)

To calculate the reverse slope, divide the rise by the run and then multiply by 100 to get the percentage.

What is a Reverse Slope?

A reverse slope refers to a slope that descends in the opposite direction of a given reference point or line. In construction and civil engineering, it is often used to describe slopes that go against the natural incline of a terrain or the intended slope of a structure. Calculating the reverse slope is crucial for designing drainage systems, roads, and other structures that require precise slope measurements for proper function and safety.

How to Calculate Reverse Slope?

The following steps outline how to calculate the Reverse Slope.

  1. First, determine the rise (R) in units.
  2. Next, determine the run (Ru) in units.
  3. Next, gather the formula from above = S = (R / Ru) * 100.
  4. Finally, calculate the Reverse Slope (S) in percentage.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

Rise (R) = 5 units

Run (Ru) = 20 units