How to Use the Cut List Optimiser

The Cut List Optimiser helps you plan cuts from standard timber lengths or standard sheet sizes. It minimises waste while accounting for blade kerf and reusable offcuts. It also estimates the total cost of materials when you enter prices.

• Use Linear Timber for studs, rails, noggins, joists, and similar cut lengths.
• Use Sheet Goods for rectangular panels cut from boards such as ply, MDF, or OSB.
• Work in millimetres or decimal inches — switch units at any time using the toolbar toggle.
• Enter optional prices per stock length to get a total materials cost estimate alongside the cut plan.
• Export finished results as CSV or as a print-friendly PDF.

1. If you work in imperial, click Metric / Imperial in the toolbar to switch to decimal inches before entering anything else.
2. Choose an optimiser mode: Linear Timber or Sheet Goods.
3. Set the blade kerf and the reusable offcut threshold in Cut Settings. If you want a cost estimate, set your currency symbol here too.
4. Select the stock lengths or sheet sizes the optimiser is allowed to use.
5. Optionally enter a price per stock length for each selected size.
6. Enter the parts you need to cut.
7. Click Optimise Cut Plan.

The Metric / Imperial button in the toolbar switches between millimetres (metric) and decimal inches (imperial). The button turns amber when imperial is active.

• Switching units converts all existing input values automatically — kerf, threshold, cut lengths, and sheet dimensions.
• When switching to imperial, stock lengths are replaced with standard US lumber dimensions (8 ft through 20 ft). When switching back to metric, standard metric lengths (2.4 m through 6 m) are restored.
• The kerf default switches from 3 mm to 0.125" (a common ⅛" table saw kerf). The offcut threshold switches from 300 mm to 12".
• All results — bar diagrams, sequence, purchase totals — are displayed in the active unit.

Imperial input format: enter all lengths as decimal inches only. For example, enter 96 for 8 ft, 48.5 for 48½ inches, or 0.125 for ⅛" kerf. Fractional inches (½") and feet-and-inches notation (8'6") are not supported — convert to a decimal first.

Entering prices turns the cut plan into a materials quote you can hand to a merchant or include in a job estimate. Pricing is entirely optional and available on all plans.

• Set your currency symbol (£, $, €, or any short symbol) in Step 2 — Cut Settings. This applies globally across all materials.
• In Step 3 — Timber Sizes & Stock Lengths, a Price per length (optional) section appears below the stock length checkboxes. Enter the price you pay per piece for each selected stock length.
• Prices are stored per-length — if 3 m CLS costs £4.20 at your merchant, enter that against the 3 m option.
• After optimising, three levels of cost information appear in the results:

1. Per line in the Purchase Summary — e.g. 5 × 3.0 m (£4.20 each) — £21.00
2. Subtotal per timber size — shown next to the material heading
3. Grand total summary card — Estimated Cost: £XX.XX appears alongside the other summary figures at the top of the results

The cost card only appears when at least one price has been entered, so the results view remains clean for users who do not need pricing.

• Timber Sizes & Stock Lengths: Add timber sizes such as 3x2, 4x2, or 2x2, rename them as needed, and tick the stock lengths available for each one. Use the custom length field to add a size your supplier stocks that is not in the default list.
• Price per length: Below the stock length checkboxes, enter the price you pay per piece for any lengths you want costed. Leave blank to skip pricing for that size.
• Add Timber Size: Use this when your job includes more than one timber section (Pro plan; Free supports up to 2 sizes).
• Linear Cut List: Enter a label, choose the timber size, add the required length in the active unit, and set the quantity.
• Load Example: Fills the table with a sample job so you can see how the optimiser behaves.
• Clear All: Removes the current timber cut rows so you can start again.

• Select the standard board sizes you want the optimiser to use.
• Add custom sheet sizes if your supplier stocks something different.
• Enter each rectangular part with width, height, and quantity in the active unit.
• Leave Rotate ticked if the part may be turned 90 degrees to improve nesting.
• The resulting layout shows how parts are placed on each sheet.

• Summary cards show the key totals for the current optimisation, including Purchased Length, Waste percentage, and — if prices are entered — Estimated Cost.
• Purchase Summary lists the stock items or sheets required, with per-line and subtotal costs when prices are set.
• Reusable Offcuts (timber jobs) lists leftovers at or above the threshold set in Cut Settings.
• Cut Plan shows each stock item with its assigned cuts, a bar diagram, and individual piece metrics.

Reusable offcut threshold tells the optimiser when a leftover piece is worth keeping. Any offcut at or above this length is shown as reusable; anything below it is treated as low-value waste.

Example: with a threshold of 300 mm (or 12" in imperial), a 420 mm leftover is listed as reusable. A 180 mm leftover is not. Set a higher threshold if you only want to keep genuinely useful offcuts; set a lower one if shorter pieces still have value in your workshop.

• Export Results CSV opens a text export you can copy into a spreadsheet or save as a .csv file. Cost data is included in the export where prices have been entered.
• Export Results PDF opens a print-friendly page in a new browser tab. Use your browser print dialog and choose Save as PDF to save a copy. The PDF includes the cut plan, purchase summary, and any cost totals.

• Save Project File downloads a .clo.json file to your computer containing all settings, timber sizes, prices, stock lengths, and cut rows.
• Load Project File restores a previously saved project, including any prices you had entered.
• Project files work offline. No account is needed to save or load them.
• Your active unit setting (metric or imperial) is not stored in the project file — the tool always opens in metric by default. Switch to imperial first if your project uses inch measurements before loading.

• Only tick stock lengths or sheet sizes you can actually buy from your supplier.
• Keep cut labels clear so the plan is easy to follow in the workshop.
• If results look wasteful, try enabling more stock lengths or adjusting the offcut threshold.
• For sheet goods, allow rotation unless grain direction or face veneer prevents it.
• In imperial mode, note that lengths like 96" (8 ft) or 120" (10 ft) are the most common US lumber lengths. Standard UK metric lengths start at 2.4 m.
• For pricing, get a current merchant quote before running the optimiser — timber prices vary and the estimate is only as accurate as the prices you enter.
• If you are quoting a job, add a small contingency above the optimiser's total to allow for measurement variation and any wasted pieces due to defects.