What Is the Dbl Winder Calculator?
Calculate double winder stairs that make a complete 180-degree turn using winder treads instead of a flat landing. This space-saving design is popular in tight residential floor plans where a full U-shaped landing isn't feasible.
How to Use This Calculator
- Enter total rise and standard tread depth.
- Set the number of winder treads for the 180° turn.
- Review tread dimensions at the walking line and narrow edge.
- Check code compliance indicators for minimum tread widths.
Why Accurate Dbl Winder Calculations Matter
Double winders save significant floor space compared to U-shaped stairs with landings, but they require careful calculation to ensure every winder tread meets the 10-inch minimum at the walking line and 6-inch minimum at the narrow edge per IRC R311.7.5.2.
Building Code References
Related Tools
Frequently Asked Questions
How many winder treads for a 180° turn?+
Typically 6 winder treads (each at 30°) for a 180° turn. Some designs use 5 or 7 treads depending on the available space and desired comfort.