LAYOUT PLANNING TOOL
Stair & Stringer Calculator
Estimate riser count, actual riser height, tread count, horizontal run, diagonal stringer length, and a planning stringer count.
How the stair estimate works
Enter the total vertical rise and a target maximum riser height. The calculator rounds up to a whole number of risers, divides the total rise evenly, then uses your tread run to estimate the horizontal footprint and diagonal stringer length.
Why the final riser height matters
Stair layouts need consistent riser heights. The calculator shows the actual equalized riser height produced by the selected total rise and riser count.
Important code and field-measurement note
This tool is for planning only. Stair requirements vary by jurisdiction and project type. Verify local rules for riser height, tread depth, nosing, landings, headroom, guards, handrails, stringer spacing, lumber sizing, and final finished-floor elevations before cutting material.
Plan before cutting
Read the stair and stringer planning guide or use the Project Planner for your material checklist.