Stair Stringer Calculator
Calculate stair riser height, tread depth, step count, and stringer length per IRC Section R311.7.
Floor-to-floor vertical distance (e.g., 105 in = 8 ft 9 in)
Horizontal stair footprint depth available
Number of Steps14steps
Riser Height7.50in
Tread Depth8.57in
Stringer Length159.5in
IRC R311.7 Code Check
- Pass: Riser height 7.50 in (must be 4-7.75 in)
- Fail: Tread depth 8.57 in (must be 10 in min.)
- Fail: Riser + tread = 16.07 in (must be 17-25 in)