Allow for cut loss while keeping usable offcuts visible.
Illustrative estimating scene. Use the source drawing, stated dimensions and calculation method for quantities.One stock piece / Two equal finished parts
Where do the 96 inches go?
Change the allowances and watch the same length budget. This uses the planner’s rule of one kerf per finished part and trim at both ends.
80 in finished parts + 0.25 in kerf + 0.5 in end trim = 80.75 in required.
Remaining length is not automatically a usable offcut. Check its clear length, profile and condition, and allow for any further cuts.
Hypothetical inch-based length study, not cutting instructions. Zero allowance is available to show the arithmetic, not to recommend a zero-width cut or no end preparation. No defects, other machining losses or stock-length variation are modeled. Plan your own part schedule.
Kerf is material removed by the cut
Use a kerf consistent with the actual blade and process. Do not assume the nominal blade body thickness equals the resulting cut width. The planner reserves one kerf for every finished part, including the final part. That intentionally conservative rule may over-allow an exact end fit; it avoids quietly assuming a final cut consumes no material.
End trim is a separate allowance
Trim removes material from the beginning and end of each stock board. Here the entered trim is applied twice per board. It is additional to the per-part kerf allowance. Decide what the trim allowance must cover in the actual process; the program cannot identify split ends, damaged material or an out-of-square end from a number.
- Stock length minus twice end trim gives usable length.
- Each part consumes its finished length plus one kerf.
- Remaining length is shown after both deductions.
Inspect close fits
A plan with almost no remainder deserves attention. Manufacturing variation, measuring error and field changes can make a mathematical fit unusable. This tool uses decimal dimensions and a small floating-point tolerance; its output is not a promise of cutting accuracy. Confirm the plan with the person doing the work before committing expensive stock.
Do not count the same loss twice
Write down what each allowance includes. In this planner, end trim is deducted twice per stock board, and each finished part uses a separate kerf allowance. If a fabrication note gives a combined preparation loss, establish whether it already includes the relevant cuts before entering separate numbers. A vague extra-waste percentage does not explain where that length went.
For the worked example, the full balance is 96 = 80 finished parts + 0.25 kerf + 0.50 end trim + 15.25 remainder, all in inches. Keep the remainder separate from unavoidable cut loss. It may be useful for another compatible part, but it is not automatically reusable inventory.
An offcut needs its own length budget
A 15.25-inch remainder cannot supply a 16-inch part. It also cannot necessarily supply a 15.25-inch finished part: under the same 0.125-inch-per-part rule, that part would need 15.375 inches before any additional preparation. Check whether the offcut has a suitable reference end and whether another trim allowance is needed; do not assume the original board’s preparation settles every later cut.
Record an offcut by measured clear length, cross-section, profile and condition in your offcut record. If stock or part dimensions change, rerun the affected pattern. A total linear-foot allowance cannot show whether the individual lengths will fit.
Worked planning example
With 96-inch stock, 0.25-inch trim at each end and 0.125-inch kerf, two 40-inch parts consume 80.25 inches of the 95.5-inch usable length. The remaining 15.25 inches is not another 16-inch part. Both trim and kerf have already been deducted.
Common questions
Why does an exact-length piece fail?
The planner reserves a kerf for that piece. If the part plus kerf is longer than usable stock, it rejects the pattern rather than silently reducing a part.
Is 1/8 inch the correct kerf?
It is a hypothetical default. Replace it with the allowance appropriate to your actual blade, setup and process.
Evidence & limits
- Calculation method: dimensional arithmetic and conservative first-fit packing
- NIST PS 20-25 — measurement, tally and softwood size basis
Reviewed September 13, 2026. Sources support their stated technical principles; this site's workflows and hypothetical examples are not product tests, supplier approvals or independently reviewed project records.