Enter the pipe length and the height difference into the calculator to determine the plumbing slope. The slope is calculated as the ratio of the height difference to the pipe length, providing the slope in inches per foot.

Plumbing Slope Formula

The following formula is used to calculate the plumbing slope.

S = frac{H}{L}

Variables:

  • S is the slope (inch per foot)
  • H is the height difference (inches)
  • L is the pipe length (feet)

To calculate the plumbing slope, divide the height difference by the pipe length. The result will give you the slope in inches per foot, which is a common measurement used in plumbing to ensure proper drainage.

What is Plumbing Slope?

Plumbing slope is the angle at which a pipe is installed to ensure that water and waste flow correctly through the plumbing system. It is crucial for the proper functioning of the drainage system, as it prevents standing water and promotes the flow of waste and water away from the building. The slope is typically measured in inches per foot of pipe.

How to Calculate Plumbing Slope?

The following steps outline how to calculate the Plumbing Slope.


  1. First, measure the length of the pipe (L) in feet.
  2. Next, measure the height difference (H) from the start to the end of the pipe in inches.
  3. Use the formula S = H / L to calculate the slope.
  4. Finally, calculate the Plumbing Slope (S) in inches per foot.
  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.

Pipe Length (L) = 50 feet

Height Difference (H) = 6 inches