Practical tools for measured work
Winder / Kite Stair Layout Calculator
Lay out a balanced quarter-turn winder stair with tread geometry, walk-line goings and a scaled plan diagram.
Calculate the layout, check the diagram, then print the result for the shop or jobsite.
Use 0 for a pointed kite winder
Measured from the inner curve
How it works
The calculator divides the total turn into equal angles about the inside centre. Each blue walk-line segment therefore has the same going. Arc going is radius multiplied by the tread angle in radians. The numbered plan and SVG provide the riser directions from the turn centre.
Example: three winders through 90 degrees each occupy 30 degrees. At a 600 mm walk-line radius, each going is 600 x pi / 6 = 314.2 mm.
Limitations and site checks
This is a geometric layout aid, not a code-compliance approval. Stair rules vary by jurisdiction and may specify where the walk line is measured, minimum going at the narrow end, headroom, rise consistency, handrails, landings and maximum turn per winder. Confirm the current local requirements and the as-built opening before cutting.
FAQ
What is a kite winder?
Why is the outside going much larger?
Can I use unequal winder angles?
Related tools
Stair Calculator
Work out riser and tread count, riser height and stair angle from total rise and run.
Baluster Spacing Calculator
Enter the railing opening, baluster width and maximum gap you intend to use to calculate an equal-spacing layout.
Fence Picket Spacing
Lay out fence picket spacing across a run, with a live diagram of the finished fence section.
Roof Pitch Calculator
Visualize roof pitch as rise/run, degrees and a scaled triangle diagram.