Enter the stair length and stair height into the calculator to determine the handrail length. This calculator helps to estimate the length of the handrail required for a set of stairs.

Handrail Length Formula

The following formula is used to calculate the handrail length.

HL = √(SL^2 + SH^2)

Variables:

  • HL is the handrail length (inches)
  • SL is the stair length (inches)
  • SH is the stair height (inches)

To calculate the handrail length, use the Pythagorean theorem to find the hypotenuse of the right triangle formed by the stair length and the stair height.

What is a Handrail Length?

Handrail length is the measurement of the handrail needed to match the diagonal distance from the top of the stair set to the bottom. This length ensures that the handrail provides adequate support and stability for individuals using the stairs. It is important for safety and compliance with building codes.

How to Calculate Handrail Length?

The following steps outline how to calculate the Handrail Length.


  1. First, measure the length of the stairs from the top step to the bottom step (SL).
  2. Next, measure the height of the stairs from the top step to the bottom step (SH).
  3. Use the formula HL = √(SL^2 + SH^2) to calculate the handrail length (HL).
  4. Finally, use the calculator above to verify your result.

Example Problem : 

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

stair length (SL) = 120 inches

stair height (SH) = 72 inches