Number of Risers
0
Home & DIY Calculator
Stair Stringer Calculator
Calculate the number of risers and treads, exact rise per step, total run, stair angle, stringer length, and the repeated rise-and-run marks used to lay out a stair stringer.
Stair Layout
Stringer layout setting
0 in rise × 0 in run
Number of Treads
0
Exact Rise per Step
0 in
Total Horizontal Run
0 in
Stair Angle
0°
Theoretical Stringer Length
0 ft
Layout Summary
What are stair rise and run?
The rise is the vertical height of each step. The run is the horizontal distance from one riser to the next. These two measurements form the repeated triangular cuts along the stair stringer.
A framing square or stair gauges can be set to the calculated rise and run. The same measurements are then marked repeatedly down the stringer board.
How the stair layout is calculated
- Divide the total rise by the maximum desired riser height.
- Round up to determine the required number of equal risers.
- Divide the total rise by that number to find the exact riser height.
- Subtract one from the riser count to determine the tread count for stairs ending at an upper floor or landing.
- Multiply the tread count by the unit run to find the total horizontal run.
Important stringer considerations
- Measure from finished floor to finished floor, not unfinished framing.
- Account for tread thickness when making the bottom and top cuts.
- Do not assume nominal lumber dimensions equal actual dimensions.
- Confirm adequate remaining wood beneath each stringer notch.
- Verify stringer spacing, attachment hardware, landings, guards, and handrails separately.