What Is the Curved Calculator?
Design elegant curved and helical staircases with our free calculator. Curved stairs create a dramatic architectural focal point with a continuous arc radius, varying tread widths, and smooth railing transitions. This tool calculates arc length, tread geometry, and structural requirements.
How to Use This Calculator
- Set the inner and outer radii of the curved stair.
- Enter the total rise and number of treads.
- Review the calculated arc lengths, tread widths at the walking line, and headroom clearance.
Why Accurate Curved Calculations Matter
Curved stairs are custom-built and expensive - typically $10,000 to $100,000+ - so accurate calculations before fabrication are essential. The walking-line tread depth must meet code minimums, and the continuous handrail requires precise radius matching.
Building Code References
Related Tools
Frequently Asked Questions
What is the difference between curved and spiral stairs?+
Curved stairs have a large radius and wide treads similar to straight stairs, while spiral stairs wrap tightly around a center column with significantly narrower treads. Curved stairs are typically more comfortable and code-friendly.