How to Mark a Board With a Stair Stringer Layout Calculator
Get the rise, run, bottom riser, and throat from the stair stringer layout tool first. This page is the square, scribe, slide sequence you use on the board. It is not a code-compliance guide.
Set the square
Set a framing square to the calculator rise on the tongue and the run on the body. Stair gauges locked on those numbers keep the setting while you slide the square down the 2x12.
Scribe the first notch
Start at the bottom end of the board (crown up). Hold both gauges against the same long edge and scribe along the square. That pair of lines is one plumb cut and one level cut.
Drop the bottom riser
The first finished riser includes tread thickness. Measure the tool’s bottom riser cut down the first plumb line and scribe a new level cut for the pad or floor.
Slide and repeat
Slide the square until the rise arm meets the last run mark. Scribe the next notch. Repeat until you have every tread the calculator listed.
Cut top, bottom, and notches
Mark the last plumb cut at the landing. Cut the notches, then the bottom and top. Check throat remaining before you commit the saw.
Bottom riser and tread thickness
Finished risers should match. Because the first tread sits on the stringer, the first plumb cut is shorter by the tread thickness. The tool prints that bottom riser cut. Do not skip it or the first and last finished rises will disagree.
Throat before you cut
After the notches, a strip of uncut wood remains along the back of the board. That is the throat. Compare it with the rise and run reference shop hints. If a long flight leaves a skinny throat, step up to 2x12 or 2x14 and recalculate.
Print when you want 1:1 lines
The on-screen diagram is scaled to fit the phone. For paper you can tape onto the board, export the paid US Letter template (0.25 in overlap, page numbers). Until you print, the marking steps on the tool page are the field instructions.
For reference only. Construction must follow local code and a qualified professional.