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Utility

Stair Calculator

Calculate the perfect stair rise and run, stringer length, and number of steps required for your deck or home project.

Stair Calculator

FAQ

Frequently asked questions

How is stair rise and run calculated?
Stair rise is the vertical height between steps, and run is the horizontal depth. Calculate the total rise and divide by the desired step height to find the number of steps.
What is the standard stair rise and run?
A common rule of thumb is the 7-11 rule: a 7-inch maximum rise and an 11-inch minimum run for safe and comfortable stairs.
How do I determine the total number of stairs?
Divide the total vertical rise by your target step rise. Round to the nearest whole number to get the total number of risers (steps).
What is stair stringer length?
The stringer is the diagonal support board. Its length is calculated using the Pythagorean theorem based on the total rise and total run.
Why must stair riser heights be identical?
Uneven stair risers create a tripping hazard. Building codes require riser heights to be identical or vary by no more than 3/8 of an inch.
What is headroom in stair design?
Headroom is the vertical clearance above the stairs. Standard building codes usually require a minimum headroom of 6 feet 8 inches.
Do I need a landing for my stairs?
Building codes typically require a landing for every 12 feet of vertical stair rise to provide a resting point and prevent long falls.