About Sheet Cut Planner — Kerf, Grain & Layout
An area estimate can promise twelve panels from a sheet even when only ten can be cut. Rectangle dimensions, saw kerf, and the direction of the face grain decide the actual layout. This planner works with one repeated rectangular part size and one stock size. It compares rows of unrotated and rotated parts, then repeats that comparison in the other cutting direction. The result is a practical shelf pattern that can be separated into strips before crosscutting.
Use it for cabinet shelves, drawer bottoms, repeated acrylic blanks, foam inserts, or workshop panels. Enter measured stock dimensions rather than relying on a nominal sheet label. The diagram numbers each finished rectangle and gives its top-left coordinates; those coordinates describe the part boundary, not a CNC tool-center path. Grain-sensitive plywood and decorative laminates should normally keep rotation off unless the design explicitly permits it.
The algorithm searches a restricted family of layouts, not every possible nesting arrangement. Its best pattern is a feasible answer, not proof that no better arrangement exists. It does not combine different part sizes, repair stock defects, account for clamps, or add machining allowance to the finished part. Add any finishing allowance to your part dimensions before planning, and check the actual sheet and saw setup before cutting.
How It Works
- Measure stock width and height. Enter the same edge allowance on all four sides; the trim value includes material lost while creating that finished edge.
- Enter the required blank width and height, then the measured saw kerf. Kerf consumes space between adjacent parts and between strips.
- Choose whether individual parts may turn 90 degrees. With rotation disabled, the part width always follows the sheet width, preserving the orientation you entered.
- Read capacity and the number of sheets needed for your order. The drawing shows a full-sheet pattern; the final sheet requires only the remaining quantity.
- Inspect the coordinates, print the result, or download the CSV. Save stores one setup in this browser; a share link carries the current dimensions and does not create an account.
Worked Example
A 2440 × 1220 mm sheet with 10 mm edge trim has 2420 × 1200 mm available. For 600 × 400 mm parts and 3 mm kerf, two unrotated rows hold eight parts. A mixed pattern holds four unrotated parts in a 400 mm-high row and six rotated parts in a 600 mm-high row. The rows occupy 1003 mm including their separating cut, so ten parts fit. An order of 24 needs three sheets: ten, ten, and four. The area-only upper bound of twelve ignores whether rectangles and saw cuts can actually be arranged.
Formulas
- Usable stock
Wᵤ = W − 2t; Hᵤ = H − 2t- Parts across a strip
n = floor((Wᵤ + k) / (w + k))- Mixed strip height
a(h + k) + b(w + k) ≤ Hᵤ + k- Order material utilization
η = 100 × Qwh / (SWH)
Standards & References
- Rectangular geometry and a two-orientation shelf heuristic derived for this planner; no claim of globally optimal nesting.
- HOMAG, intelliDivide cutting documentation: saw kerf, trim, and permitted panel orientation are distinct planning inputs — https://docs.homag.cloud/docs/en/intellidivide-processing-parameters-optimization-parameters-cutting
- NIST SI Units — Length: international inch = exactly 25.4 mm — https://www.nist.gov/pml/owm/si-units-length
Frequently Asked Questions
Why can an area estimate overstate my sheet yield?
Area division ignores shape. A remaining region may have enough square millimetres but be too narrow for another part. Kerf, edge trimming, and fixed grain orientation remove still more options. The area bound is therefore a ceiling, not a cutting layout.
Does this sheet planner guarantee minimum waste?
No. It compares mixed rows in two cutting directions for identical rectangles. A more general nesting solver may find a better pattern, particularly with several part sizes. This tool makes its actual arrangement inspectable instead of calling an area ratio an optimized plan.
Where is the kerf measured in the drawing?
Kerf is the gap between neighboring finished rectangles and between neighboring strips. Coordinates mark finished edges. The initial trim is a total edge allowance that includes its own cut loss, so a separate extra kerf is not subtracted from every trimmed edge.
How do I preserve plywood grain direction?
Turn off 90-degree rotation and enter the part width in the same grain orientation as the stock width. Every part then keeps that orientation, even if the preferred strip-cut direction changes. The planner does not infer grain from material names.
Can I use the CSV directly as machine code?
No. It lists part-boundary coordinates and sizes, with units. It contains no tool offsets, feed rates, hold-down strategy, or safe travel commands. Use it as a shop list or an input to a properly configured manufacturing workflow.