Stair Length Calculator

How to Use the Stair Length Calculator

1. Enter the rise (height of each step) in the first input field. This is the vertical measurement from the top of one step to the top of the next step.
2. Enter the run (depth of each step) in the second input field. This is the horizontal measurement from the front of one step to the back of the next step.
3. Select the unit of measurement (inches or centimeters) from the dropdown menu.
4. Click the "Calculate" button to compute the diagonal stair length.
5. The calculator will display the stair length (diagonal) based on the Pythagorean theorem.

Understanding Stair Dimensions

The stair length calculation is based on the Pythagorean theorem, which states that in a right-angled triangle, the square of the length of the hypotenuse (c) is equal to the sum of the squares of the other two sides (a and b): c² = a² + b².

In stair construction, the rise and run form the two shorter sides of a right triangle, and the stair length is the diagonal (hypotenuse) that connects them.

Typical Stair Dimensions

For comfortable stair climbing, standard rise and run dimensions typically follow these guidelines:

• Rise: 7-8 inches (18-20 cm)
• Run: 10-11 inches (25-28 cm)
• Stair length: Varies based on total height and number of steps

Important Notes

This calculator provides the diagonal length of stairs. For complete stair construction, you'll also need to consider:

• Headroom (minimum 80 inches or 203 cm)
• Platform width
• Handrail requirements
• Local building codes and regulations