Trim cut planner
Plan continuous pieces, not just a total length
Enter each required finished segment separately. The planner allocates those lengths to interchangeable stock pieces of one entered length, charges your entered cut allowance per segment, and reports a candidate layout and material cost. A 5 ft segment must fit one stock; the tool never joins shorter leftovers to make it.
This is quantity planning after segment requirements have been established. Angles, joints, grain direction, profiles, damaged ends and cutting safety are not modeled. Verify those project-specific conditions outside the tool before relying on a purchase list.
Build a piece list with one unit
Record an identifier and finished length for each segment, including repeated lengths. Three separate 5 ft pieces are three entries, not one 15 ft entry. The input accepts commas or new lines and up to 200 segments. Keep the original piece list so equal-length items are not accidentally omitted.
Use feet for segments, stock and cut allowance. A hypothetical allowance of 0.01 ft equals 0.12 in; it is not 0.01 in or a recommended saw setting. Convert other length units with the length converter before entering them. Price is the entered USD price for one full stock piece.
The tool uses the same allowance for every segment, including the final one on each stock. This conservative arithmetic convention can overstate consumption when a final cut is not needed. It is not a physical cut-by-cut instruction or an estimate of every real source of waste.
Example 1: three 5 ft pieces need three stocks
For this synthetic example, use: segments 5, 5 and 5 ft, stock 8 ft, cut allowance 0.01 ft per segment and synthetic price $12 per stock.
| Stock | Finished segment | Charged allowance | Remaining length |
|---|---|---|---|
| 1 | 5 ft | 0.01 ft | 2.99 ft |
| 2 | 5 ft | 0.01 ft | 2.99 ft |
| 3 | 5 ft | 0.01 ft | 2.99 ft |
Each consumes 5.01 ft. Two such pieces cannot fit one 8 ft stock, so the candidate requires three stocks and costs $36. The 8.97 ft remainder is three separate 2.99 ft pieces, not a continuous length capable of supplying another 5 ft segment.
Reconcile the quantities: 15 ft finished + 0.03 ft allowance + 8.97 ft remainder = 24 ft stock. This checks the model’s ledger, not whether every remnant is practically usable.
Example 2: an exact-fit layout with unequal pieces
Use finished lengths 6, 3.8, 4 and 4 ft, stock 10 ft, allowance 0.1 ft per segment and $12 per stock. The longest-first order is 6, 4, 4, 3.8; the output still keeps each original input identity.
| Stock | Original segments placed | Finished sum | Allowance sum | Remainder |
|---|---|---|---|---|
| 1 | 6 and 3.8 ft | 9.8 ft | 0.2 ft | 0 ft |
| 2 | 4 and 4 ft | 8 ft | 0.2 ft | 1.8 ft |
The candidate uses two stocks for $24. Total finished length 17.8 plus allowance 0.4 plus remainder 1.8 equals 20 ft. Read the actual layout rather than assuming segments remain in the order entered or that the two 4 ft entries represent one item.
What longest-first placement does and does not promise
The algorithm sorts by segment-plus-allowance length, then puts each segment in the first existing stock with enough remaining room. Otherwise it opens another stock. Identical input produces a deterministic result. The result is feasible within these simplified length constraints, not a guaranteed minimum purchase.
A synthetic counterexample makes that limit concrete. Use 6, 5, 3, 2, 2 and 2 ft, stock 10 ft and zero allowance solely to study allocation. The tool places 6 + 3 on stock one, 5 + 2 + 2 on stock two, and the last 2 on stock three. Remainders are 1, 1 and 8 ft.
An alternative grouping is 6 + 2 + 2 and 5 + 3 + 2, using two stocks. At $12 each, the tool’s candidate costs $36 while that hypothetical grouping costs $24. This does not mean zero allowance is appropriate for real cuts; it demonstrates that the heuristic can miss a smaller layout even in a simplified problem.
Check infeasible inputs before comparing cost
A finished 8 ft segment with 0.01 ft allowance exceeds 8 ft stock and is rejected. Setting allowance to zero just to make a physically incompatible piece pass would change the assumptions, not solve the actual constraint. The total-length guide explains why an aggregate quotient cannot establish fit.
The tool assumes every stock has the same usable length and can supply every listed segment. It does not deduct owned offcuts, assign varying stock sizes, check profiles or decide splices. If those are material constraints, the single-length model may not represent your purchase.
Review the candidate layout before ordering
| Check | What to confirm |
|---|---|
| Piece list | Every original identifier occurs once, including duplicates. |
| Individual fit | Each finished segment plus charged allowance fits one stock. |
| Per-stock fit | Segment consumption sums do not exceed that stock’s usable length. |
| Remainders | Lengths are separate offcuts, not one combined continuous stock. |
| Cost | Count is multiplied by full-stock price; tax and delivery are separate. |
| Practical constraints | Real material conditions have been checked outside the simplified model. |
Retain both inputs and the stock-by-stock layout after recalculating. Woodgrain’s resource center, checked by direct public retrieval October 3, 2026, discusses measuring moulding and cut allowances. Its percentage example is not adopted here and does not validate our per-segment allowance or algorithm. The planner is not installation or safe-cutting guidance.