Calculate wall angle, height, or distance from any two values, plus ladder working length, base distance, angle, and a 4:1 working-length setup reference.

Right-triangle geometry on level ground against a vertical wall. Geometry alone cannot establish ladder safety.

Wall Angle Formula

WA = ATAN (H / L) ร— 57.2958

Variables:

  • WA is the Wall Angle (degrees)
  • H is the wall height (ft)
  • L is the length away from the wall (ft)

To calculate Wall Angle, take the inverse tangent of the wall height divided by the length away from the wall, then multiply by 57.2958 to express the result in degrees.

How to Calculate Wall Angle?

The following steps outline how to calculate the Wall Angle.

  1. First, determine the wall height (ft). 
  2. Next, determine the length away from wall (ft). 
  3. Next, gather the formula from above: WA = ATAN (H/L) * 57.2958.
  4. Finally, calculate the Wall Angle.
  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.

wall height (ft) = 5

length away from wall (ft) = 4

FAQ

What is the significance of calculating the Wall Angle?

The calculation gives the angle above horizontal for a right triangle formed by a vertical wall and level ground. Angle alone does not establish structural stability or ladder safety.

Can the Wall Angle formula be used for any type of wall and ladder setup?

The formula assumes a vertical wall, level ground and straight measurement lines. It does not cover every wall, support or ladder type, and does not replace manufacturer instructions or applicable safety rules.

How does changing the wall height or the length away from the wall affect the Wall Angle?

Increasing the wall height or decreasing the length away from the wall will increase the Wall Angle, making the slope steeper. Conversely, decreasing the wall height or increasing the length away will decrease the angle, making the slope gentler.

Is there a maximum or minimum Wall Angle for safety reasons?

For non-self-supporting ladders, OSHA 1926.1053(b)(5)(i) specifies a horizontal base distance approximately one-quarter of the working length along the ladder from its foot to top support. This corresponds to about 75.52 degrees. It is not height divided by four, and an angle between 70 and 80 degrees is not by itself a safety pass. Follow the ladder instructions and all applicable requirements.