Why "lumber cost" is misleading
Most first-time project budgets blow up at the lumber yard, the hardware store, or the home center — and rarely in the same place. The reason: a typical project's final cost is split across at least five categories, and people estimate only one or two.
A representative breakdown for a mid-size furniture project:
- Lumber (rough): 30-40% of cost
- Sheet goods (plywood, MDF): 10-15%
- Hardware (slides, hinges, screws): 10-20%
- Finishing materials (sandpaper, glue, finish): 5-15%
- Time (your labor): 30-50% — often the biggest single line
The "hidden 30%" comes from underestimating finishing and time, then having to re-buy materials because of mistakes or running out. This calculator surfaces those costs up front.
What about shop overhead?
This calculator doesn't include:
- Electricity for shop tools (~$0.50-1.00/hour for a typical small shop)
- Blade and bit wear (~$0.50-2.00 per project)
- Sharpening stones and honing compounds (amortized over years)
- Shop fixtures (workbenches, clamps — already-owned capital)
For a hobby project, these are minor. For a side-business pricing custom work, add 10-15% to cover them.
Common budgeting traps
- Forgetting finishing consumables. A 30-board-foot project can easily use $30-50 in sandpaper, glue, and finish. New woodworkers routinely budget $0 here.
- Not counting trial cuts. First-time joinery often takes 2-3 attempts. Budget scrap material for those.
- Underestimating time. "This should take a weekend" usually means 16 hours of shop time plus 8 hours of setup, sharpening, and finishing. Multiply by your hourly value to see the real cost.
- Skipping contingency. Hardware store runs add up. A 15% contingency covers them without dipping into project margin.
How to use this for pricing custom work
If you're building for a client, set your hourly rate at 2-3× what you'd pay yourself as an employee — because your rate has to cover business overhead (insurance, marketing, tools, workspace) and unpaid time (quoting, sourcing, accounting).
A common mistake is to price materials at cost and add a small markup. That's not enough — materials should be marked up 10-20% to cover sourcing time, handling, and waste that you can't pass to the client.
Frequently asked questions
Should I include tool depreciation?
For hobby projects, no — your tools are already-paid capital. For business pricing, yes — divide the tool cost by expected lifetime projects and add to each.
What about sales tax?
Add your local rate as a separate line. This calculator doesn't assume a tax rate because it varies by jurisdiction and by whether you're a business with a resale certificate.
How accurate is this for exotic woods?
For exotics, increase your contingency to 25-30% — exotic wood is more likely to arrive with defects, and mistakes cost more because the material itself is expensive.