WoodWorkCalc

Woodworking foundations / Lesson 4 of 6

Basic

Cut lists, kerf & rough stock

Prove whether a set of parts fits the available stock.

5 min estimated reading · Hands-on practice is additional and self-pacedJump to worked example

Before you begin

Paper or a spreadsheet, finished dimensions, stock dimensions, and a measured kerf. Start with the paper example.

You will learn to

  • Distinguish finished size from a rough blank.
  • Account for each actual separating cut.
  • Reject a high-yield layout that cannot be supported or cut safely.

Helpful first

01 / Understand the relationship

The idea behind the work

A cut list is not just a table of dimensions. It is a plan for turning real stock into finished parts without forgetting the material that disappears to trimming, kerf, defects, or a safer sequence.

Kerf
The width of material removed by a cut, not necessarily the blade plate thickness.
Rough allowance
Additional stock reserved for milling or trimming before final sizing.

Begin with finished dimensions, then back into stock

List the parts that the project requires, then add the material needed to mill, trim, and cut them cleanly. The initial blank is often larger than the finished part by design.

Treat kerf as consumed stock

Each separating cut removes material. Include the blade or cutter path in the plan, especially when you are close to the limit of a board or sheet, and leave room for any final clean-up cut.

Plan a controlled sequence, not only a tight layout

The layout with the least waste is not automatically the best shop plan. Keep support, grain direction, safe handling, part labels, and the order of operations visible before you start breaking down material.

Keep these foundations in mind
  • A cut list must show more than finished dimensions: quantity, rough size, grain direction, trim, kerf, and part identity all matter.
  • Kerf is stock removed by the cut, so it belongs between parts.
  • The tightest nesting plan may not be the best safe breakdown plan.

02 / Work through an example

Do three 300 mm parts fit?

A 1,000 mm board needs three 300 mm finished parts. For this simplified length-only plan, allow 20 mm total end trim including its cutting loss, plus three separate 3 mm part-separating cuts. No additional milling allowance is assumed.

Illustrative example · assumptions stated above
Stock useCalculationLength
Finished parts3 × 300900 mm
Separating kerfs3 × 39 mm
Trim allowanceTotal reserved20 mm
Remainder1,000 − 900 − 9 − 2071 mm
What this teachesThe length budget fits under these assumptions. Width, defects, grain, support, and the real cutting sequence still need their own checks.

Change the stock budget

Predict the remainder before changing the board length. When does this plan stop fitting?

Length-only exercise: three identical parts, three separating cuts, and 20 mm total trim including trim-cut loss. No additional milling allowance. This is not a safe cutting plan.

71.0 mm remaining

1000 − (3 × 300) − (3 × 3) − 20 = 71.0 mm. The length budget fits; check every other layout and process constraint separately.

03 / Put it to work

A small, deliberate practice session

Start with the paper or screen review in “Before you begin.” Only proceed to physical work when you have the instruction, equipment, and controls for that operation. Do not rush to match a reading-time estimate.

  1. Choose three simple parts from one board or sheet.
  2. Add rough size, trim, kerf, grain direction, and labels before you draw the layout.
  3. Write the cut sequence that keeps the material supported and the parts traceable.

Common mistakes to watch for

  • Optimizing material yield before deciding which face or grain needs to show.
  • Forgetting the last trim cut after a rough breakdown.
  • Losing part identity after the first crosscut.

Ready for a deeper challenge?

Rebuild the example with rough-milling allowance on each part. Compare a length-only budget with a labeled two-dimensional layout.

Bench reminders for this topic

Study reminders only. Recheck the current job using the complete machine-specific procedure every time.

  • List quantities and finished dimensions for every part.
  • Add rough-milling and trim allowance where the process needs it.
  • Include kerf, cutter loss, and sheet trim in the stock plan.
  • Keep grain direction and show faces visible in the layout.
  • Label parts and choose a safe breakdown sequence before cutting.

04 / Explain it back

Can you reason through it?

Say or write your answer before opening the explanation. If you need the hint, revisit the example and try again.

1. Why does this example count three kerfs instead of always using parts minus one?

Give me a hint

Draw the offcut after the last part.

Reveal the reasoning

Each of the three parts is separated from the remaining board. Other layouts can need a different number of cuts. Count the actual cut plan rather than applying one rule to every layout.

2. Would a 905 mm board fit the same plan?

Give me a hint

Add all consumption before comparing stock length.

Reveal the reasoning

No. This plan consumes 929 mm, so it is short by 24 mm. Do not hide the missing material by removing a required allowance.

05 / Keep the evidence

Your learning notebook

Tick what you can explain in your own words. These are learning goals—not a machine preflight, permission to operate, or a qualification.

Record: Stock dimensions, finished and rough part sizes, grain direction, kerf, trim allowance, cut order, and actual yield.

My evidence, observations & next test

No notes recorded. Use this space for your observations.

Loading your device notebook… 0/5,000 characters.

Check each learning goal above to enable self-review. Every lesson remains open whether or not you mark it reviewed.

Apply the idea with the right tool

Use the calculator after you can explain its inputs. Results still need to be checked against the actual job.

Sources & further study

Original teaching examples are illustrative. These public references support further study; third-party sources retain their own licenses and are not all open-source material.