Construction · free · no sign-up
Stair Calculator
Plan a staircase: the number of steps, the exact riser height and the tread depth.
About the Stair Calculator
Plan a staircase: the number of steps, the exact riser height and the tread depth.
How to use the Stair Calculator
- Enter the Total Rise, the Total Run and your Preferred Riser Height in inches.
- Press Calculate Stairs.
Formula and method
Number of risers = total rise ÷ preferred riser, rounded. Actual riser = total rise ÷ number of risers. Tread depth = total run ÷ number of treads.
Worked example
A total rise of 120 in with a 7 in riser gives 17 risers of about 7.06 in each.
Tips
- Building codes limit riser height and tread depth. Check your local rules.
- Keep all risers identical for safety.
Frequently asked questions
What is the ideal riser height?
Usually between 6 and 8 inches, with 7 inches being common.