Enter your lumber's Thickness, Width, Length, and Quantity into the Lumber Calculator to get the Board Feet per Piece, Total Board Feet, and Total Cubic Feet — then add a Price per Board Foot to see your Total Cost before you ever set foot in the lumber yard.
Board Feet per Piece
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Total Board Feet
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Total Cost
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Total Cubic Feet
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A board foot is a unit of volume for lumber equal to one square foot that is one inch thick (144 cubic inches). It's calculated using the formula: Board Feet = Length (ft) × Width (in) × Thickness (in) ÷ 12.
Lumber is often sold in quarters: 4/4 = 1 inch, 5/4 = 1.25 inches, 6/4 = 1.5 inches, 8/4 = 2 inches. These refer to rough dimensions before surfacing.
Hardwood lumber is typically more expensive and sold by board foot, while softwood is often sold by linear foot. Hardwoods range from $3-20+ per board foot, while softwoods are usually $1-5 per board foot.
Plan for 10-15% extra lumber to account for cuts, mistakes, and defects. For complex projects with many cuts, consider adding 20% to your calculated quantity.
Yes, this calculator works for all lumber types. Pressure-treated lumber follows the same board foot calculations, though pricing is typically higher than regular softwood.
Nominal dimensions are the rough-cut size (like 2×4), while actual dimensions are smaller after drying and planing (1.5×3.5 for a 2×4). This calculator uses actual dimensions for accuracy.
For wall framing, studs are typically spaced 16 or 24 inches on center. Divide wall length by stud spacing, add 1, then add extra studs for corners, doors, and windows.