How this calculator works
Rough lumber yields far less than its nominal board footage. Once it is jointed, planed, ripped square and the defects are cut out, a realistic yield is 60% to 75% — so a project needing 10 usable board feet may take 14 board feet of rough stock.
The other routinely missed cost is finishing. Sanding through grits, then multiple coats with cure time and sanding between them, is often as many hours as the build.
The formula
- Lumber = usable board feet × cost per board foot ÷ (1 − milling waste %)
- Shop labour = milling and assembly + sanding and finishing, at their own rates
- Machine setups = ⌈ quantity ÷ pieces per setup ⌉
- Price = (cost per piece + fixed fee ÷ quantity) ÷ (1 − target margin − fee %)
What to watch for
- Enter the board feet that end up in the finished piece and let the waste percentage work out what you have to buy. Rough stock yields 60% to 75% once it is milled square and defects are cut out.
- Machine setup is charged once per job. This is the single biggest reason a batch of ten shelves costs so much less per unit than one shelf, and why quoting a repeat piece at the original price leaves money on the table.
- Finishing time is active time only. Cure time between coats costs no labour, but it does occupy shop space and delays delivery, which is worth remembering when quoting a lead time.
- Furniture-scale work often needs a crate. Building one is a small project of its own and belongs in the packaging figure, not absorbed.
Common mistakes
- Costing lumber at the finished board footage with no milling allowance.
- Charging machine setup per piece, which makes batches look uneconomical.
- Under-counting sanding and finishing, frequently a third of total shop time.
- Forgetting crating and delivery on large work, where they can exceed the hardware cost.
Frequently asked questions
How do I price a woodworking project?
Work from usable board feet plus shop hours. Enter what ends up in the piece and let the milling waste percentage account for what you actually buy, then add machine time, hardware, finish and a realistic finishing labour figure. The result is usually well above the "materials times three" rule, because the hours dominate.
How much lumber waste should I allow?
For rough sawn stock, 25% to 40% depending on the species, the grade and how fussy you are about grain match. Surfaced four-sides material wastes less, around 10% to 20%, but costs more per board foot to begin with. Track your own yield on a few projects and use that.
What shop rate should I charge?
Enough to cover your labour plus the shop that makes it possible. Many small shops land between $35 and $60 an hour for the bench rate, with machine cost accounted separately. If you are unsure, work it out from the labour cost and overhead allocation calculators rather than picking a number.
Why is my second identical piece so much cheaper?
Because design, planning and machine setup are charged once. On the example project that is nearly two hours before any wood is cut. Set the quantity above one and you will see the per-piece price drop sharply — which is also the honest basis for a discount on a repeat order.