How it works
Pieces are sorted from longest to shortest. Each piece goes into the already-started board where it leaves the least remainder; only when it fits nowhere is a new board started.
Several strategies are tried — shortest suitable board, longest board, each single stock length — and every finished board is moved to the shortest stock that still holds its cuts.
For smaller jobs every combination of cutting patterns is searched as well, so the plan is provably the best possible — the result then says so.
The plan with the lowest cost wins when every stock length has a price; otherwise the one with the least bought length, then the fewest boards.
Every cut between two pieces removes one kerf. The final offcut is reported after the last kerf, so what you see is what you actually keep.
What the calculator assumes
- One-dimensional cutting: width and thickness of pieces equal the stock.
- Pieces can be cut in any order and boards have no defects.
- This is an optimised plan, not a proven optimum; on small jobs it is usually equal to the best by hand.
Questions
- What kerf should I enter?
- The width of the saw cut: about 2–3 mm (up to 1/8 in) for a typical circular or mitre saw blade, less for thin-kerf blades and Japanese pull saws. Check your blade.
- Why add a squaring cut?
- Factory ends are often not square or are damaged. A few millimetres trimmed from every board avoids pieces coming out short.
Planning aid only. It does not size structural members or check loads — follow the manufacturer's instructions and your local building rules.