2D Guillotine Cutting Optimizer
Plan sheet cutting with minimal waste: enter your sheet size, kerf, edge margin and parts — get an optimized layout, a cut-by-cut sequence and reusable remnants.
2D Guillotine Cutting Optimizer — plan your cuts
What does this cutting optimizer do?
The guillotine cutting optimizer arranges rectangular parts on standard sheets so that every cut runs from one edge of the current piece to the opposite edge — the classic guillotine (glass/panel saw) constraint. It minimizes the number of sheets and the leftover waste.
You define the sheet dimensions, how many sheets you have, the blade kerf, an optional edge margin and the minimum size that still counts as a reusable remnant. Then you list your parts with quantities. The tool runs a genetic algorithm in your browser and returns the best layout it finds, plus the exact order of cuts needed to produce it.
Results include per-sheet diagrams, a numbered cutting sequence for each sheet, a summary of material used versus waste, and a breakdown of reusable remnants versus scrap.
Tips and common mistakes
Tips
- Measure your blade kerf before planning — a 3 mm kerf over 20 internal cuts wastes 60 mm of material that a no-kerf plan simply ignores.
- Leave an edge margin if the sheet edges are damaged or need a clean border; the optimizer keeps every part inside the usable area.
- Enable rotation for parts that can be cut either way — rotated parts often pack noticeably tighter.
- Set a realistic minimum remnant size: small offcuts below that size are treated as scrap, not storage.
- If the run is incomplete (not all parts placed), increase the sheet quantity or reduce piece sizes — the summary tells you which part type could not fit.
Common mistakes to avoid
- Forgetting the kerf — layouts drawn without kerf gaps fail on the saw because parts become slightly larger than planned.
- Confusing sheet quantity 0 (auto: as many as needed) with a fixed number of sheets.
- Ignoring grain direction: the optimizer can rotate parts, so if direction matters, disable rotation for those parts.
- Trusting a no-margin plan on sheets with damaged or rounded edges.
2D Guillotine Cutting Optimizer — frequently asked questions
What is a guillotine cut?
A guillotine cut is a straight cut that runs from one edge of the current rectangle to the opposite edge, splitting it into two pieces. Many panel saws and glass cutters can only make guillotine cuts, so layouts that require non-spanning cuts (T-junctions) cannot be executed on them. This tool only generates layouts that can be produced with guillotine cuts, in a real cutting order.
Why does the tool add the kerf to each piece?
Each cut removes material equal to the blade thickness. The optimizer bakes the kerf into the part dimensions (piece size + kerf) and the usable sheet size (sheet size − margins + kerf), so the diagram shows the real kerf gap between adjacent parts without needing a separate overlap pass. This is the same trick professional nesting software uses.
How does the optimizer find a good layout?
It runs a genetic algorithm: a population of candidate solutions is scored by a three-level objective (fewest sheets, then fullest last sheet, then best cut alignment and leftover consolidation). The best candidates are recombined and mutated over thousands of generations, with the greedy large-parts-first layout as a guaranteed baseline.
What do the reusable remnants mean?
After all parts are placed, every remaining rectangle is compared against the minimum remnant size you set. Rectangles at least that large in both dimensions are marked as reusable (you can store them for a later job); smaller ones are marked as waste.
Is the result guaranteed to be the absolute minimum waste?
No. Sheet cutting is NP-hard, so the tool returns a near-optimal solution found within a time budget (usually under a few seconds in your browser). For most practical jobs the result is within a fraction of a percent of optimal; for critical jobs, run the optimizer a few times with different seeds and compare.
Do I need to enter dimensions in millimeters?
No — the tool accepts mm, cm, meters, inches and feet. All values are converted internally; results are displayed in the same unit you chose.
How this calculator works
The optimizer expands the problem (kerf baked into parts, margins subtracted from the sheet), classifies parts into large/medium/small groups, and decodes each candidate genome with a GLAS-style strip decoder that is guillotine-safe by construction. A seeded genetic algorithm (population 40, elitism, tournament selection, OX crossover, swap/flip/selector/inverse mutations) evolves layouts in parallel island restarts under a time budget. The best solution across all islands is decoded into final coordinates and a complete cutting sequence. All computation runs locally in your browser — nothing is uploaded.
Limitations
- Results are near-optimal, not provably optimal.
- Only axis-aligned rectangles are supported; no irregular or circular parts.
- Sheet quantity 0 assumes you may use as many sheets as needed (capped at 200).
- The tool does not account for grain direction, blade length limits, or part warping; disable rotation where grain matters.
Sources and references
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