Construction calculator
Stair Calculator
Plan a straight flight of stairs from total rise and preferred tread depth.
Your measurements
Estimated result
Number of risers1
Actual riser height0 in
Number of treads0
Total run0 in
Stair angle0°
Stringer length0 in
Planning estimate only. Check product specifications, site conditions and local codes before ordering or building.
How the stair calculation works
Risers = round up(total rise ÷ target maximum riser). Actual riser = total rise ÷ risers. For a simple flight, treads are usually one fewer than risers.
Planning notes
This tool is for planning a simple straight flight. Building-code limits for riser height, tread depth, landings, headroom and handrails vary by location, so use the result as a layout estimate rather than approval to build.
- Always check your local building code before construction.
- Finished-floor heights matter: measure from finished lower floor to finished upper floor.
Keep calculating
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