Enter the angle of the slope in degrees into the calculator to determine the excavation slope; this calculator can also evaluate the angle of the slope given the excavation slope is known.

Excavation Slope Formula

The following formula is used to calculate the excavation slope:

 Slope = tan(θ)

Variables:

  • Slope is the slope of the excavation
  • θ is the angle of the slope in degrees

To calculate the excavation slope, take the tangent of the angle of the slope in degrees.

What is an Excavation Slope?

An excavation slope refers to the inclined boundary surface created during excavation work, such as digging a trench, pit, or other depression in the earth’s surface. The angle of the slope is determined by the stability of the soil or rock being excavated and is designed to prevent the sides of the excavation from collapsing. The slope’s angle can vary from vertical to horizontal, depending on the soil type, moisture content, and other factors. The Occupational Safety and Health Administration (OSHA) provides guidelines for the maximum allowable slopes to ensure worker safety during excavation work. These guidelines take into account the type of soil (such as solid rock, Type A, B, or C soil) and the depth of the excavation.

How to Calculate Excavation Slope?

The following steps outline how to calculate the Excavation Slope.


  1. First, determine the height of the excavation slope (h) in meters.
  2. Next, determine the horizontal distance of the excavation slope (d) in meters.
  3. Next, gather the formula from above = Excavation Slope = h / d.
  4. Finally, calculate the Excavation Slope.
  5. After inserting the values of h and d into the formula 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.

height of the excavation slope (h) = 10 meters

horizontal distance of the excavation slope (d) = 5 meters