Timber cut list planning: board lengths, saw kerf and worked example
Before buying boards, turn your timber cut list into a board-by-board allocation. Adding up finished lengths gives a starting point, but saw kerf, end trims and the way pieces fit together determine how many lengths you need. Use this guide for boards, battens and mouldings of one matching section.
Separate each timber section
Group pieces by species or material, width, thickness and profile. List stock lengths you have or can buy and their quantities. A board that is long enough may still have the wrong section. Keep sheet materials out of a length-only plan because sheet cutting also depends on width and layout.
Decide what each length represents
Take finished lengths and quantities from the project drawing. Include any deliberate extra length for a later operation in your input. For mitred trim, agree on the measurement reference first: long-point and short-point lengths are different. Keep units consistent across stock and pieces.
Make room for saw kerf and trimming
Use the kerf for your actual blade and saw setup. A stock length equal to the sum of the pieces may be too short once cutting losses are added. Decide whether stock ends are usable or need trimming, and account for trims separately. Do not count the same trim twice by deducting it from stock and adding it again as an allowance.
Inspect boards before accepting the plan
Length alone does not describe knots, splits, grain or visible-face requirements. Inspect boards and adjust usable stock or piece assignments for defects. Check each board allocation, then decide which offcuts are worth keeping. A short remnant is useful only if its section and condition suit a later piece.
Worked example: pieces, cuts and remaining stock
Fictional teaching example — static sample data, not a customer job or calculated result.
Available stock: Two 2,400 mm boards of the same section.
Required pieces: 1,000 mm × 2; 700 mm × 2; 600 mm × 1. Five pieces total 4,000 mm.
Assumptions: square cuts, usable starting ends, no end trims or defects, and a 3 mm kerf. Each finished piece needs one separating cut because each stock length leaves a remainder. Cut counts change if the final stock end becomes a finished piece or extra trimming is needed. These allocations illustrate a feasible plan; they are not a claim of an optimal layout.
| Stock | Length | Finished pieces | Piece total | Cuts / kerf | Remaining |
|---|---|---|---|---|---|
| Board 1 | 2,400 | 1,000 + 700 + 600 | 2,300 | 3 / 9 | 91 |
| Board 2 | 2,400 | 1,000 + 700 | 1,700 | 2 / 6 | 694 |
Check the arithmetic: 4,800 mm stock = 4,000 mm finished pieces + 15 mm kerf + 785 mm remaining stock. The offcuts are 91 mm and 694 mm. Count the 694 mm piece as reusable only if it suits another job; total remaining length alone does not tell you its value.
For each stock length, check: finished piece lengths + (separating cuts × kerf) + trim allowance ≤ usable stock length. Then reconcile piece quantities across the whole plan. Here, usable stock means the measured length before the separately stated trim allowance.
Common timber cut planning questions
How many boards should I buy from a cut list?
Total required length divided by stock length gives a lower bound, not a purchasing answer. Here, 4,000 ÷ 2,400 rounds up to two boards, and the allocation confirms that two fit with the stated kerf. Other combinations may need more boards because the pieces do not fit together.
Will two 1,200 mm pieces fit a 2,400 mm board?
Not if a separating cut removes material and both pieces must finish at exactly 1,200 mm. Their lengths already consume the whole board. Use a longer usable stock length or revise the requirements before cutting.
Can I use this for plywood or cabinet panels?
Use a 2D sheet layout for panels. This guide allocates length along matching boards, battens and mouldings; it does not model panel width, grain orientation or nesting.
Before you run the planner
- Boards match the required material and section.
- Lengths refer to the correct finished measurement.
- Saw kerf, end trims and defects are accounted for.
- Board allocations produce the required piece quantities.