Stair Calculator

Calculate rise, run, and stringer layout for safe and comfortable stairs.

Measurements

Total Rise (inches)

Vertical distance from lower floor to upper floor level.

Target Step Rise (in)

Step Run (in)

Number of Steps

Stair Angle

37.6°

Exact Rise per Step7.714"

Target Run10"

Total Run (Horizontal)10.83 ft (130.0")

Stringer Length (Approx)14.73 ft

Step dimensions fall within typical residential building codes (7.75" max rise, 10" min run).

Total Rise: The vertical distance from the top of the finished lower floor to the top of the finished upper floor.
Total Run: The horizontal distance the stairs will cover.
Rise (Unit Rise): The vertical height of a single step. Ideal is ~7-7.5 inches.
Run (Unit Run/Tread): The horizontal depth of a single step. Ideal is ~10-11 inches.
Stringer: The structural board that supports the treads and risers.

The "17-18" Rule: Rise + Run should equal roughly 17 to 18 inches.
Example: 7.5" Rise + 10" Run = 17.5" (Good)