Lay out a staircase stringer from rise and run.
The combined rise set and run set form a right triangle whose hypotenuse is the long edge of the stringer board. The length of a 2x stringer decides whether one standard board spans a staircase or you need to splice it.
Stair Stringer
Stringer = sqrt(rise set^2 + run set^2)
Stringer = sqrt(rise set^2 + run set^2) The combined rise set and run set form a right triangle whose hypotenuse is the long edge of the stringer board.
The length of a 2x stringer decides whether one standard board spans a staircase or you need to splice it.
This calculator takes 3 inputs: Total rise, Riser height, Tread run. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.