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

## Stair Tread Formula

The following formula is used to calculate the length of stair tread.

T = (R^2 + S^2)^{(1/2)}

Variables:

- T is the length of the stair tread (inches) R is the rise of the stair (inches) S is the run of the stair (inches)

To calculate the length of the stair tread, square the rise of the stair and the run of the stair separately. Add the two results together and then take the square root of the sum. This will give you the length of the stair tread.

## What is a Stair Tread?

A stair tread is the horizontal component of a staircase where you place your foot as you ascend or descend. It is the flat surface that makes up each step, providing a stable and secure area to step on. The depth and width of the tread can vary depending on the design of the staircase. It can be made from various materials such as wood, metal, or concrete, and may sometimes have a non-slip surface or carpeting for added safety.

## How to Calculate Stair Tread?

The following steps outline how to calculate the length of a stair tread using the formula T = (R^2 + S^2)^(1/2).

- First, determine the rise of the stair (R) in inches.
- Next, determine the run of the stair (S) in inches.
- Next, substitute the values of R and S into the formula T = (R^2 + S^2)^(1/2).
- Finally, calculate the length of the stair tread (T).
- After inserting the values 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 of the stair (R) = 8 inches

Run of the stair (S) = 10 inches