Calculate board feet and optional cost with quantity, unit conversion, and wastage allowances.

Board Dimensions

Length of one board.

Unit for board length.

Width of one board.

Thickness of one board.

Unit for width and thickness.

Quantity and Pricing

Number of boards.

Allowance for cuts and defects.

How lumber pricing is estimated.

Price for the selected mode.

How this calculator works

A board foot is a volume measure: 1 inch thick × 12 inches wide × 1 foot long.

  1. board_feet_each = (thickness_in × width_in × length_ft) ÷ 12
  2. board_feet_total = board_feet_each × quantity × (1 + wastage%)
  3. boards_to_buy = ceil( quantity × (1 + wastage%) )
  • Hardwood is sold by the board foot; dimensional softwood is usually sold by the piece — pick the matching pricing mode.
  • Use nominal thickness (e.g., 1″ for a "5/4" board) — that is what board-foot pricing assumes.

Common questions

What is a board foot?

A board foot is the volume of a piece of lumber 1″ thick × 12″ wide × 1 ft long — 144 cubic inches. Hardwood is almost always priced this way. Dimensional softwood (2×4s, 2×6s) is priced per piece.

Should I use nominal or actual lumber dimensions?

Nominal. A "2×4" measures 1.5″ × 3.5″ actual, but board-foot pricing uses 2 × 4. Hardwood is quoted in "quarters" (4/4 = 1″, 5/4 = 1.25″) which are nominal — use those.

How much wastage for hardwood?

10% covers most rough cuts. Bump to 15–20% when you need clear stock with no defects, when the cut list has lots of short pieces, or when you're working with figured/specialty wood that's more expensive to re-order.

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Framing lumber is sold by the piece and billed by the board foot, and the difference is where short orders happen. Miss the rim plates, miss a couple of king studs at the openings, miss the doubled corners and you’re sending someone for a Home Depot run while the rest of the crew waits with nail guns idle. This calculator returns a stud count for the wall you described — including the plates, the openings, and the corners — plus board-foot equivalents so the supplier’s quote and your takeoff agree.

What you’ll get

Enter wall length, ceiling height, stud spacing (16 or 24 inch on-centre), and board length (8, 10, 12 ft). The calculator returns line studs, top and bottom plates, opening framing, board-foot total, and an estimated cost if you supply a per-board or per-board-foot rate.

A sample wall

Say you’re framing a 12 ft wall at 16 inch on-centre, 8 ft ceiling, no openings. Line studs come from the wall length divided by spacing, plus one for the end:

studs = (12 × 12) ÷ 16 + 1 = 10 line studs

Add the doubled-end corner stud and the plates — top, bottom, and the cap that ties one wall into the next:

total = 10 line + 2 corner + (3 × 12 ft plates ÷ 8 ft) ≈ 17 pieces of 8 ft 2×4

Each opening adds two king studs, two jack studs, a header, and a sill — roughly 6 extra pieces per window or door. A wall with one window comes out around 23 pieces. The supplier prices these at the per-piece rate; the bill of materials uses board feet, which for 8 ft 2×4s comes out to 5.33 BF per piece.

Spacing, and where the defaults come from

16 inch on-centre is the residential framing standard for load-bearing walls in Ontario and most of North America. 24 inch on-centre (advanced framing) is allowed for non-loadbearing partitions and saves about 30% of the line-stud count, but the drywall has to span the wider gap and your nailer crew may push back. 12 inch spacing shows up only in shear walls and hurricane regions — if your engineer hasn’t asked for it, you don’t need it.

When to lean on it, when not to

This is a single straight-wall calculator. It handles individual partition runs, garage walls, and the long walls of a rectangular addition. It is not the right tool for full house framing takeoffs, walls with more than three openings, gable ends, or anything where engineered lumber, jack-rafters, or trusses interact with the wall plates. For those, hand the plans to your supplier — most lumber yards offer a free framing takeoff for orders over a threshold.

Board foot = thickness × width × length, all in inches, divided by 144. So an 8 ft 2×4 = 1.5 × 3.5 × 96 ÷ 144 ≈ 5.3 BF. Nailers, hangers, fasteners, and waste are not in the calculator — figure 5% extra studs for splits and crooked pieces.

If you’re framing anything that touches a building permit, structural engineering, or an addition that ties into existing framing, a sit-down with a contractor or framer who can read the plans is usually cheaper than reordering after a permit revision.

Other calculators on this site

If you’re scoping a whole project, you’ll usually need more than one of these. They share the same approach — plain math, honest about edge cases, with the practical notes someone who has done the work would actually need.

  • Asphalt Calculator. Tonnage for a driveway, parking patch, or walkway pour, including the depth-to-tonnage curve a supplier will quote against.
  • Concrete Pour Calculator. Cubic yards of concrete for a slab, footing, or post hole, plus the waste factor most pours actually need.
  • Drywall Calculator. Sheets of drywall and bundles of mud for a renovation room, plus the cut and waste allowance.
  • Excavation Calculator. Cubic yards of dirt to remove for a basement, pool, or footing — including the bulking factor that surprises first-timers.
  • Fence Calculator. Lineal feet of fence, post count, rails, and gates for a property line that is rarely perfectly straight.
  • Fill Calculator. Cubic yards of fill for a regrade, a backyard level, or a low spot, plus a sensible compaction factor.
  • Paint Calculator. Gallons of paint for a room, plus the coverage difference between primed and unprimed surfaces.
  • Tile Calculator. Square footage of tile for a floor or wall, plus the breakage and cut waste a real installation needs.

Next step

What happens next

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