Stair Rise and Run Calculator
Calculate stair dimensions for safe and comfortable stairs
About this calculator
The Stair Rise and Run Calculator helps you determine the optimal dimensions for safe and comfortable stairs by calculating the ideal rise (vertical height) and run (horizontal depth) of each step. This tool ensures your stairs comply with building codes and safety standards while providing maximum comfort for users. Proper stair dimensions are crucial for preventing accidents, reducing fatigue, and creating accessible pathways in residential and commercial buildings.
How to use
Enter your total stair height and desired number of steps into the calculator. The tool will automatically calculate the rise per step and recommend the appropriate run depth based on standard building ratios. Review the results to ensure they meet local building codes and adjust the number of steps if needed.
Frequently asked questions
What is the ideal rise and run ratio for stairs?
The standard ratio is 7-inch rise with 11-inch run, following the rule that rise plus run should equal 17-18 inches for optimal comfort and safety.
What are the maximum and minimum stair dimensions allowed?
Most building codes require rise between 4-8 inches and run minimum 9 inches, with maximum rise of 7.75 inches for residential stairs.
How do I calculate the number of steps needed?
Divide your total stair height by your desired rise per step, then round to the nearest whole number to determine step count.