Determine riser count and tread run metrics for stair layouts.
Calculator Parameters
Enter details and click calculate to view the results instantly.
Calculation Examples
Scenario Inputs
Output Result
rise : 100, targetRiser : 7
Risers: 14 steps at 7.14 inches, Treads: 13 steps
About Stair Calculator
Stair Riser and Run Calculator. Determine riser count and tread run metrics for stair layouts. Starlightopia provides this tool completely free and online, optimized for instant, accurate computations.
How It's Calculated
How do you calculate the total number of treads needed for a staircase?
The total number of treads is always exactly one less than the total count of risers, as the top step meets the landing floor.
Technical Specifications
CategoryConstruction
Target ValueStair Layout Dimensions
Inputs Required (2)
Total Vertical Rise (Inches) (number)
Target Riser Height (Inches) (number)
Frequently Asked Questions
What is a comfortable target riser height for residential stairs?
A target riser height of 7 inches is widely considered the standard for safe and comfortable residential stairs.
What is the standard rule of thumb for stair design safety?
The traditional safety rule states that twice the riser height plus the tread run depth should equal between 24 and 25 inches.
What is the maximum allowed riser height under the International Residential Code (IRC)?
The IRC sets the maximum safe height for a residential stair riser at 7.75 inches.
Why must all risers within a single staircase be uniform?
Variations in riser heights can break a person's stride and create a serious tripping hazard.
How do you calculate the total number of treads needed for a staircase?
The total number of treads is always exactly one less than the total count of risers, as the top step meets the landing floor.