Everyday Converters
Stair Calculator
Calculate stair rise, run, number of steps, stringer length, stair angle, and total horizontal run from total height and tread depth.
Result
--What does this calculator do?
Calculate stair rise, run, number of steps, stringer length, stair angle, and total horizontal run from total height and tread depth.
Formula
Number of risers = total rise ÷ target riser height. Actual riser height = total rise ÷ number of risers. Total run = tread depth × number of treads. Stringer length uses the Pythagorean theorem.
Example calculation
For a 108 inch total rise with a 7 inch target riser, the calculator estimates 15 risers, 14 treads, a 70 inch total run with 10 inch treads, and the stringer length from rise and run.
Common use cases
- Deck stair planning
- Porch and basement stairs
- Quick stair layout estimates
Limitations and accuracy notes
This calculator is for quick planning and education. Results depend on your inputs and may not include every real-world rule, fee, tax, health factor, local requirement, or professional standard.
Stair Calculator FAQ
Is this calculator free?
Yes. It gives quick estimates directly in your browser.
Should I use this as professional advice?
No. Use it as a planning aid and confirm important decisions with a qualified professional.