To price lumber from a per-MBF quote:divide the price per thousand board feet by 1,000 to get the price per board foot, then multiply by each piece’s board feet (thickness × width × length in inches ÷ 144). A 2×4×8 is 5.33 board feet, so at $500/MBF it costs about $2.67. The calculator above does this for every nominal size automatically.
How the Lumber Calculator works
The lumber calculator computes board feet, total linear feet, and material cost for framing, decking, and finish lumber. A board foot is the standard unit for pricing dimensional lumber: 1 inch thick × 12 inches wide × 12 inches long, or 144 cubic inches.
Board feet per piece = (nominal thickness × nominal width × length) ÷ 144, using nominal dimensions (a 2×4 is figured as 2 × 4, not its actual 1.5 × 3.5 inches), which is the industry standard. Multiply by quantity for total board feet, then by 1.10 to add a 10% waste allowance for cuts, defects, and layout. Total linear feet is simply length × quantity. Cost is the board feet (with waste) multiplied by the price per board foot, where the price per board foot is the MBF price ÷ 1000. MBF means thousand board feet, the standard wholesale unit; the default is $650/MBF for 2026 framing lumber, which equals $0.65 per board foot.
When you pick a nominal size the tool also shows the actual dressed cross-section (for example, a 2×6 is actually 1.5 × 5.5 inches) so you know the real dimensions you will build with, even though board feet are always priced on the nominal size.
Worked example: 10 pieces of 2×4 at 8 feet each. Board feet per piece = (2 × 4 × 96) ÷ 144 = 5.33 BF. Across 10 pieces that is 53.3 board feet, and with the 10% waste factor, 58.7 board feet. At $650/MBF ($0.65 per board foot) the material cost is about $38, and total linear feet is 8 × 10 = 80 LF.
Frequently Asked Questions
Does the calculator use nominal or actual dimensions for board feet?
Board feet are calculated from nominal dimensions: a 2×4 is figured as 2 by 4 inches, not its actual dressed size of 1.5 by 3.5 inches. This is the lumber-industry convention, so mill and yard quotes match. The tool still displays the actual cross-section for reference when you select a nominal size.
How much does the 10% waste factor add to my order?
After totaling board feet, the calculator multiplies by 1.10, adding 10% for saw kerf, end trims, defective boards, and layout. On a 100 board-foot order that is an extra 10 board feet. Framing with many short cuts may warrant more, while long straight runs may need less.
How do I convert an MBF price to cost per board foot?
Divide the MBF price by 1,000. MBF is the price per thousand board feet, so $650/MBF equals $0.65 per board foot and $900/MBF equals $0.90. The calculator applies this rate to your total board feet (with waste) to estimate cost.
Why does a 2×4 measure less than 2 by 4 inches?
Lumber is named by its rough-sawn size, then planed and dried to a smaller finished dimension. A 2×4 ends up 1.5 by 3.5 inches, and a 2×6 ends up 1.5 by 5.5 inches. The calculator prices board feet on the nominal name but reports the actual size so your framing math is accurate.