How the results are calculated
SzyjTo uses transparent planning formulas and a fast rectangular packing heuristic.
Fabric length
The tool adds allowances to each edge, applies shrinkage, calculates pieces across the roll and multiplies the rounded row length by the number of rows.
Cutting layout
Pieces are sorted by size and placed into the first existing row where they fit. Rotation is attempted only when enabled. This is a heuristic, not a proof of an optimal result.
Limitations
The first version handles rectangles. It does not interpret commercial pattern PDFs, curves, grain lines drawn inside a pattern or fabric defects.