Linear Cutting Stock & Order Optimizer

What does a linear cutting stock optimizer do?

Turn a list of finished part lengths into an order for uncut bars, timber strips or pipes.
Stock means the full-length material sold by the supplier; a part is the finished length your project needs.
Dividing total part length by stock length can miss incompatible combinations and material removed by the blade.
This calculator assigns every requested part to a specific bar and checks the capacity of each bar.

Use it when preparing a DIY repair, hobby project or a cutting quote for a family member.
Unlike an area-based renovation budget, it compares individual part lengths, quantities and per-bar prices.
Save the plan to check dimensions with the cutting shop before placing an order.
The output is a purchase and layout review, rather than a machine instruction or structural assessment.

Group matching materials before calculating

Every stock option is assumed to be available in unlimited quantities.
If an option is unavailable, remove it and calculate again; if supply is limited, ask the shop to review the actual quantities.
Existing offcuts, knots and other defects, grain direction, angled cuts and joined pieces are excluded.
The model does not determine whether a bar is safe to clamp or whether a member is strong enough for its intended use.

Inputs and units

All lengths use millimetres to one decimal place.
Multiply centimetres by ten and verify the usable measured length rather than relying on the nominal size alone.
All prices use KRW; convert other currencies consistently before entering them.
Use the same tax basis for every quote: shipping, labour and additional tax are not automatically added.

Capacity calculation including kerf

This conservative model reserves one kerf per part, including the last part.
A process that reuses the original end face or omits the final cut can produce a different layout.
A part as long as the entire bar will not fit if a positive kerf is entered.
Include trimming kerfs in total end trim; do not add them again to the per-part kerf allowance.

Two 497mm parts fit exactly into a 1,000mm bar with 3mm kerf and zero end trim.
Two 497.1mm parts exceed that capacity and require two bars.
The packing arithmetic uses integer tenths of a millimetre to preserve these boundaries.
Measurements and machine tolerances still need to be checked with the shop.

What does the optimality status mean?

A heuristic cost is a feasible upper bound: every requested part fits under the entered assumptions, but a cheaper arrangement may exist.
No invented accuracy percentage or savings guarantee is attached to it.
Plans tied on cost and total length can distribute offcuts differently; maximizing reusable offcut length is not a separate objective.
Identical inputs produce a deterministic result, including the search-limit status.

Step-by-step use and shop review

1. Check finished dimensions against the drawing and separate materials and cross-sections.
   
2. Enter part lengths and quantities, then add actual stock sizes and per-bar quotes.
   
3. Confirm blade kerf, total end cleanup and clamping allowances with the shop.
   
4. Calculate and reconcile the stock order and bar-by-bar sequences with your requested parts.
   
5. Read the optimality status, save the TXT report and print it or send it for a cutting quote.
   

Editing inputs removes the old result so a previous order cannot be mistaken for the current plan.
Calculate again to obtain a new layout.
If any part fits no available bar, the calculator identifies its request row and withholds the entire order plan.
It does not silently produce a partial order; add a longer option or correct the measurements first.

Worked example: ordering two different bar lengths

The two bars cost KRW 28,000 in total.
Of the 5,400mm purchased, finished parts account for 4,800mm, kerf for 24mm, end trim for 20mm and offcuts for 556mm.
Length yield is approximately 88.89%.
Both offcuts are below 300mm, so this layout has 0mm of reusable candidates and 600mm of estimated scrap.
Other tied layouts may distribute the offcuts differently.

Separate yield, total offcuts and scrap

Yield describes the proportion of purchased length that becomes finished parts.
It does not measure a price discount or production speed, and the cheapest plan need not have the highest yield.
Total offcuts include both reusable candidates and short remnants; neither should be confused with sawdust removed by the blade.
Changing the reusable threshold changes the classifications but not the cost objective.

An offcut long enough to keep may still have unsuitable end faces, defects or the wrong section for your next project.
Do not assume that a length candidate is saleable inventory or automatically deduct its value from a future order.
Record its material, section and measured length separately if you retain it.

Practical uses for repairs and hobby projects

Only include products the supplier can actually sell in the required material and quality.
When a quote changes, update price and availability and compare the assumptions in the old and new reports.
An old online price list or a quote for a different thickness should not be treated as the current price for your project.

Frequently asked questions