108 in total rise
- Actual riser
- 7.7142857143 in
- Treads
- 13
- Total run
- 130 in
- Angle
- 37.6476206401 deg
Stair rules are safety critical and local. Check code, landings, headroom, handrails, and uniformity before building.
Stair Calculator
Use this free stair calculator to estimate riser count, actual riser height, tread count, total run, and stair angle for a simple stair layout.
Research-backed assumptions Formula steps Examples included Private in-browser use
Formula steps
- Divide total rise by the target riser height and round to a whole riser count.
- Divide total rise by that riser count to get the actual riser height.
- Use one fewer tread than risers for a typical straight stair run.
How to use the stair calculator
- Enter total rise, target riser height, and tread depth in inches.
- Press Calculate stair layout to see risers, treads, run, and angle.
- Use the result for rough layout conversation only.
- Check local code for uniformity, handrails, headroom, landings, and finished surfaces.
Common uses
Estimate a simple straight stair layout.
Find actual riser height after rounding to a whole step count.
Estimate total horizontal run.
Check the stair angle for planning conversation.
Examples
14 risers
Simple stair estimate
Riser and run estimate
Frequently asked questions
Plain-language answers about when to use the tool, what it does with your inputs, what to double-check, and how privacy works.
When should I use the Stair Calculator?
Use it when your task matches one of these common needs: Estimate a simple straight stair layout. Find actual riser height after rounding to a whole step count. It works best when you already know the values, dates, units, or settings the page asks for.
What is the Stair Calculator doing with my inputs?
In plain language: The calculator divides total rise by target riser height, rounds to a whole riser count, then calculates actual riser height and run from tread depth. The examples on the page are there so you can compare your inputs with a filled-out calculation before copying the answer.
What should I double-check before trusting the answer?
Stairs are safety critical. Check local building code, uniformity, headroom, landings, handrails, and professional requirements before building. Also check that you used the right unit, date, scale, or mode because small input changes can change the result.
Does the site save what I enter?
No. The calculator runs in your browser tab. Your recent answers stay only on the page while you use it, and they are not sent to a server.