Calculator · Panels & cutting
Cut List Optimizer
Plan straight part cuts from available board, panel, lumber, or timber stock and estimate theoretical remainder. Use it when turning a project parts list into a practical cutting plan before marking and cutting material.
Basic cut list optimizer
This uses a practical first-fit decreasing approach. It is not guaranteed to find the absolute optimal layout, and you should verify the cuts manually before cutting lumber/timber.
Result
Enter stock and part lengths, then calculate a basic layout.
How it works
This is a basic cut list optimizer for boards, rails, trim, and similar straight lumber/timber cuts. It expands the required parts by quantity, converts lengths to millimetres, sorts parts longest to shortest, and places each part into the first stock board where it fits.
For n requested parts assigned to one stock piece, the optimizer allows n − 1 internal kerfs between those requested parts. The existing stock ends act as fit boundaries. A positive remainder may need another cut before it becomes a separate offcut, so the displayed value is theoretical rather than guaranteed reusable stock.
The approach is practical first-fit decreasing, not mathematical perfection. Results may not be the absolute optimal layout, and they do not account for grain direction, defects, board selection, joinery orientation, or workshop cut order.
- Expand required parts by quantity.
- Convert all stock and part lengths to millimetres.
- Sort parts from longest to shortest.
- For each part, try the first existing stock board where it fits; if none fit, start a new stock board.
- Internal kerf allowance = max(n − 1, 0) x saw kerf, where n is the number of requested parts on that stock piece.
- Allocated stock use = sum of requested part lengths + internal kerf allowance.
- Theoretical remainder = stock board length - requested part lengths - internal kerf allowance.
- Estimated cost = stock boards needed x stock board price.
Worked example
With 1000 mm stock, requested parts of 600 mm and 397 mm, and a 3 mm kerf, both parts fit exactly: 600 + 397 + 1 x 3 = 1000 mm. The two requested parts use one internal kerf and leave 0 mm theoretical remainder.
A single 600 mm requested part uses zero internal kerfs for allocation and leaves a 400 mm theoretical remainder. Physically separating that remainder may consume another kerf; end squaring, cleanup cuts, damaged ends, and defect removal may reduce it further.
Common mistakes
- Assuming a basic optimizer always finds the absolute best layout.
- Forgetting saw kerf, blade choice, end trimming, and cleanup cuts.
- Ignoring knots, splits, bow, twist, grain direction, and visible-face selection.
- Cutting directly from the screen without marking and verifying the real boards.
Common questions
Is this cut list optimizer mathematically perfect?
No. It uses a practical first-fit decreasing method. It can be useful, but it may not find the absolute optimal layout.
How is saw kerf handled?
For n requested parts assigned to one stock piece, the optimizer allows n − 1 internal kerfs between those requested parts. Final separation, end squaring, and cleanup cuts are not included.
Why are there n − 1 kerfs for n requested parts?
Only the internal separations between requested parts affect packing feasibility, and the existing stock ends act as boundaries. A physical cut may still be needed to remove a single part from longer stock or separate a positive remainder.
Is the displayed remainder a guaranteed usable offcut?
No. It is a theoretical remainder before final separation or end trimming. A final separating cut, end squaring, cleanup cuts, damaged ends, or defects may make the physically reusable offcut smaller.
Can I use metric and imperial lengths together?
Yes. Each part row can use its own unit, and the calculator converts everything to millimetres internally.
Does this account for defects or grain direction?
No. Check each board manually for defects, grain, visible faces, and joinery needs before cutting.
Can this estimate stock cost?
Yes. Enter an optional stock board price and currency symbol to estimate basic stock-board cost.