Stair Calculators — Stringers, Rise & Run

Issued

1 of 2

Stair Stringer Calculator

Risers, riser height, treads, total run, the stringer diagonal, the layout line and the throat from a measured total rise, with the 2x12 to buy and how many of them a width takes.

Open sheet →

In the set, not issued

S-106

Concrete Steps Calculator

Volume of a run of steps from rise, run, width and landing.

Not issued

Quick reference

A measured total rise divided at a 7 in target riser, with a 10 in tread
Total rise	Risers	Riser height	Treads	Total run	Stringer diagonal
2 ft	3	8 in	2	1 ft 8 in	2 ft 7 1/4 in
3 ft	5	7 3/16 in	4	3 ft 4 in	4 ft 5 13/16 in
4 ft	7	6 7/8 in	6	5 ft	6 ft 4 13/16 in
4 ft 9 in	8	7 1/8 in	7	5 ft 10 in	7 ft 6 1/4 in
6 ft	10	7 3/16 in	9	7 ft 6 in	9 ft 7 1/4 in
8 ft	14	6 7/8 in	13	10 ft 10 in	13 ft 5 5/8 in
9 ft	15	7 3/16 in	14	11 ft 8 in	14 ft 8 13/16 in

Every row is division, not a table anyone published: the rise you measured over the riser height you are working to, rounded to the nearest whole riser, and the run that follows from the tread you chose. Type your own figures on sheet S-301 and the stringer diagonal, the layout line and the throat move with them. The only cited figures in the set are five prose provisions of AWC DCA 6-2015 — a 2x12 minimum stringer, three cut stringers minimum, an 18 in maximum spacing, a landing above 12′-0″ and a handrail from four risers up. DCA 6 is a prescriptive guide based on the IRC. The code your jurisdiction has adopted governs, and it is the document to check before you cut.