What is a board foot?

A board foot is a volume measurement for lumber equal to a piece that is 1 inch thick, 12 inches wide, and 12 inches long. Hardwood dealers and specialty lumber yards almost always quote price per board foot rather than per piece, so knowing how to calculate board feet is essential for estimating material cost before you buy.

Why do I need a waste factor?

Raw boards contain knots, checks, twist, and other defects that reduce usable yield. Every cut also removes material as sawdust. Many shops add 15 to 20 percent waste on top of their net board foot calculation. Projects with figured grain, complex joinery, or tight color matching may need 25 percent or more to account for selective cutting.

Do softwood 2x4s use board feet?

Dimensional softwood lumber sold at home improvement stores is priced by the linear foot or per individual piece, not by board feet. Board foot pricing is standard at hardwood yards and specialty suppliers selling species like oak, maple, walnut, and cherry. If you are ordering from a hardwood dealer, always confirm which unit the price quote refers to.

Can I mix board sizes in one project?

Yes. Add one row for each different board dimension in your project. The calculator shows board feet per piece and a row subtotal for each size, then combines all rows into a single project total with your waste factor applied. This lets you price out a mixed lumber order with one calculation rather than running separate estimates.

Lumber Board Foot Calculator

One board foot is a piece 1 inch thick, 12 inches wide, and 12 inches long (144 cubic inches). Hardwood lumber is often priced per board foot.

UnitsImperial (in / ft)Metric (cm / m)

Lumber pieces

LabelSpecies

QtyThickness (in)Width (in)Length (ft)

Project settings

Waste factor (%)Price per board foot ($)

Raw board feet

16.00

With 15% waste

18.40

Estimated cost

$82.8

Board-by-board breakdown

Piece	Qty	T	W	L	BF each	BF total
Shelf slatsOak	4	1 in	6 in	8 ft	4.00	16.00

Board foot totals are estimates. Confirm grade, surfacing, and pricing with your supplier before you order.

How this tool works

Enter thickness, width, and length for each lumber piece, set quantity, then add a waste percent for cuts and defects. The calculator sums board feet and applies waste once on the project total.

Worked example

Four shelf slats at 1 by 6 by 8 feet each are 4 board feet per piece, or 16 board feet raw. With 15% waste that is 18.4 board feet to buy.

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Frequently asked questions

What is a board foot?
A board foot is a volume measurement for lumber equal to a piece that is 1 inch thick, 12 inches wide, and 12 inches long. Hardwood dealers and specialty lumber yards almost always quote price per board foot rather than per piece, so knowing how to calculate board feet is essential for estimating material cost before you buy.
Why do I need a waste factor?
Raw boards contain knots, checks, twist, and other defects that reduce usable yield. Every cut also removes material as sawdust. Many shops add 15 to 20 percent waste on top of their net board foot calculation. Projects with figured grain, complex joinery, or tight color matching may need 25 percent or more to account for selective cutting.
Do softwood 2x4s use board feet?
Dimensional softwood lumber sold at home improvement stores is priced by the linear foot or per individual piece, not by board feet. Board foot pricing is standard at hardwood yards and specialty suppliers selling species like oak, maple, walnut, and cherry. If you are ordering from a hardwood dealer, always confirm which unit the price quote refers to.
Can I mix board sizes in one project?
Yes. Add one row for each different board dimension in your project. The calculator shows board feet per piece and a row subtotal for each size, then combines all rows into a single project total with your waste factor applied. This lets you price out a mixed lumber order with one calculation rather than running separate estimates.