Riser tool
Stringer tool in Riser
Cut stringers laid out properly: equal risers, tread run, notch geometry, throat depth, stringer count and the board lengths to buy — saved to the job with the runner alongside it.
A cut stringer is unforgiving. Round the riser height instead of the riser count and the last step is wrong; forget to drop the bottom of the board by one tread thickness and the first step is a trip hazard. The stringer tool inside Riser does the layout arithmetic and the checks in one pass, then keeps the result with the rest of the job.
What it gives you
- Equal riser heights from the total rise, with the tread count for a flush top step.
- Notch layout for a framing square, plus the total run of the flight.
- Throat depth behind each notch, with a warning under 3 1/2in.
- Stringer count from the stair width and tread material spacing.
- Board diagonal plus cutting waste, rounded to a stock length.
- An approximate runner length for the same flight, so both trades are budgeted at once.
Free version on this site
The same layout, with no sign-in, is on the stair stringer calculator. Pair it with the deck stair calculator for exterior steps, and once the carcass is built use the stair runner calculator — or the stair runner length calculator for a full flight with landings — to price the soft finish.
Frequently asked questions
What does the stringer tool in Riser do?
It turns a total rise, tread run and stair width into a full cut stringer layout: equal riser heights, tread count, notch geometry, throat depth left behind each notch, the number of stringers the stair width and tread material need, and the board length to buy including cutting waste.
How is it different from the free stringer calculator?
The maths is the same and stays free on this site. Inside Riser the layout is saved against a project, exported as a branded cut list or PDF, and combined with the runner length so a single job record covers both the carpentry and the soft finish.
Does it check throat depth?
Yes. It reports the narrowest strip of timber left behind each notch and warns when it drops below 3 1/2in, which is the point at which you should move up a board size or reduce the tread run.
Do I need an account?
No account is needed for the free calculator on this site. A free Riser account adds saving, cut lists, PDFs and client-facing quotes.