Quick answer
- Measure finished-floor to finished-floor total rise.
- Enter total rise and your maximum riser height in Tools → Stair Calculator.
- Verify actual rise, tread count, total run, and headroom against local code.
Inside the App
The workflow at a glance
This image is from the current Construction Pro project and shows the product interface behind this guide.
Step by Step
Calculate Stair Risers, Treads, and Stringer Layout
Follow the sequence and keep units visible at every handoff.
Step 1
Measure the finished total rise
Measure vertically between finished floor elevations. Include known finish-floor buildup rather than measuring only the rough framing.
Step 2
Choose the riser limit
Enter the maximum allowed riser height for the project. Local requirements vary, so the app is a layout aid—not a substitute for code review.
Step 3
Set tread depth
Enter the target tread or unit run. The tool calculates the number of treads and total horizontal run.
Step 4
Verify before cutting stringers
Check that every riser is equal, confirm top and bottom finish conditions, and compare the result with available stairwell length and headroom.
Field Examples
Three practical checks
Example 1
Standard interior stair
A 105-in total rise with a 7.75-in maximum produces 14 risers at 7.5 in each.
Example 2
Deck stair
Measure from finished deck surface to the landing elevation, not from the bottom of the joist.
Example 3
Remodel opening
Compare calculated total run with the actual opening before cutting any stringer.
Common mistakes
What to verify
- Using rough-floor elevations when finish thickness is known.
- Assuming tread count equals riser count; a typical flight has one fewer tread.
- Cutting before checking headroom, landing, nosing, and local stair rules.
Related guides
Keep working
Can I use this result without checking it?
No. Confirm measurements, units, assumptions, and applicable code before cutting material, ordering supplies, or issuing a quote.
Does Construction Pro guess missing values?
No. Its calculators use explicit formulas and the inputs you provide; missing field conditions still require professional judgment.
Can I keep the calculation with a job?
Yes. Save verified calculations in a project and add a descriptive note so the crew can see what the result means.
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