Total rise108 in
Risers14 at about 7.71 in
Treads13 at 10-1/2 in
Code checksIRC R311.7
Stairs are all math before the first cut. Get the riser count right and the rest falls into place.
The layout
- Total rise: 108 in floor to floor.
- Risers: 14 at about 7.71 in (under the 7-3/4 in IRC limit).
- Treads: 13 at 10-1/2 in, for a total run of 11.38 ft.
- Headroom: 6 ft 8 in minimum along the whole stair.
Steps
- Measure total rise with the finished floors in mind.
- Lay out one stringer with a framing square and stair gauges, cut it and test it in place.
- Use it as a template for the others.
Sources
- City of Boise handout on IRC Section R311.7.5, stair treads and risers
- City of Des Moines residential stairs handout (2012 IRC): headroom 6 ft 8 in, handrail 34 to 38 in
Sources last checked 1 November 2026.
Calculators for this project
Frequently asked questions
How many stairs for a 9 ft basement?
14 risers and 13 treads at a 7-3/4 in maximum riser.
