Woodworking Project Calculator
Enter your project’s dimensions, board thickness and width, and a waste allowance, and this calculator estimates the board feet of lumber you need and the total material cost — the same board-foot math professional shops use to quote furniture and cabinetry jobs.
Quick Answer
Enter your project’s dimensions, board thickness and width, and a waste allowance, and this calculator estimates the board feet of lumber you need and the total material cost — the same board-foot math professional shops use to quote furniture and cabinetry jobs.
Woodworking Project Calculator
Enter your values below for an instant result, then see the formula, worked example, and common mistakes.
Enter your project dimensions and click calculate.
How to Use This Calculator
Break the project into its overall length, width, and height (for a box-shaped piece like a cabinet or bookshelf) or just length and width for a flat panel like a tabletop or cutting board.
3/4 in (0.75 in) is the standard surfaced (S4S) thickness for most furniture-grade hardwood; pick the board width you intend to buy or resaw down to.
Professional shops typically budget 10-15% extra board footage for defects, miscuts, and grain-matching; complex joinery or highly figured wood can push this to 20-25%.
Hardwood lumber is priced per board foot and varies widely by species — check your local supplier or hardwood retailer for current pricing before finalizing a budget.
Use the board-foot total to plan your lumber order in standard board lengths, since suppliers sell full boards, not exact cut lengths.
Formula
Board feet = (Thickness in inches x Width in inches x Length in feet) / 12. This is the standard hardwood lumber industry formula — one board foot equals a piece of wood 1 in thick, 12 in wide, and 12 in long (144 cubic inches).
Surface area (box-shaped project) = 2(L x H) + 2(W x H) + (L x W). This estimates the combined side, end, and top/bottom panel area, which is then converted to linear feet of your chosen board width and priced as board feet.
Reference Table: Typical Board Foot Costs by Species (2026)
| Species | Typical price per board foot |
|---|---|
| Poplar | $4-$6 |
| Red Oak | $5-$8 |
| Hard Maple | $6-$9 |
| Black Walnut | $10-$16 |
| White Oak | $7-$11 |
| Exotic hardwoods (e.g. Wenge, Bubinga) | $18-$35+ |
Common Mistakes to Avoid
- Confusing linear feet with board feet — a 10 ft long, 12 in wide, 1 in thick board is 10 board feet, not 10 linear feet of material cost, since board feet accounts for width and thickness too.
- Forgetting that rough-sawn lumber loses roughly 25% of its thickness when surfaced (planed) on both faces — a rough 4/4 (one-inch nominal) board typically finishes at about 13/16 in to 3/4 in thick.
- Skipping the waste allowance entirely — even experienced woodworkers lose material to milling defects, grain matching, and measuring errors, so a 0% waste budget almost always runs short.
- Pricing all species the same — domestic hardwoods like poplar and oak can cost 3-5x less per board foot than walnut or imported exotics, so species choice dramatically changes total budget.
When the Estimate May Be Wrong
This calculator gives a simplified planning estimate based on straightforward box or panel geometry. It does not account for joinery losses (dovetails, mortise-and-tenon waste), grain-matching requirements for visible panels, curved or angled cuts that increase waste, or the cost of hardware, finish, and fasteners. For complex furniture designs, add a larger waste margin and consult a detailed cut list.
FAQs
What is the formula for board feet?
Board feet = (thickness in inches x width in inches x length in feet) / 12. One board foot equals 144 cubic inches of wood, the volume of a board 1 in thick, 12 in wide, and 12 in long.
How much extra lumber should I buy for waste?
Most woodworkers budget 10-15% extra for standard projects, and 20-25% extra for projects requiring grain matching, curved cuts, or complex joinery.
Why is my surfaced lumber thinner than the nominal size?
Lumber sold as 4/4 (one inch) is rough-sawn at that thickness, then loses about 1/8 to 3/16 in per face during planing (surfacing), finishing at roughly 13/16 in to 3/4 in thick.
Is board foot pricing the same for all wood species?
No — domestic species like poplar, oak, and maple typically run $4-$9 per board foot, while premium and exotic species like walnut or bubinga can cost 2-5x more.
Sources and Methodology
Board foot formula and lumber industry conventions sourced from the Hardwood Manufacturers Association and Woodworkers Source’s published board-foot guidance. Waste allowance and rough-to-surfaced thickness loss figures reflect standard cabinet/furniture shop practice as documented by hardwood suppliers including North Castle Hardwoods and Bell Forest Products.
