Lumber Calculator
ConstructionCalculate total board feet and material cost for your lumber order. Enter thickness, width, length, quantity, and price per board foot for an instant estimate.
10 pieces
pieces
Total Cost
$350
Total Board Feet
100
What is a Lumber?
A Lumber Calculator converts the physical dimensions of a lumber order — thickness, width, length, and quantity — into total board feet and total material cost. Board feet is the standard volume unit used across the US lumber industry, and getting an accurate total is essential whether you're framing a deck, ordering hardwood for a furniture project, or comparing quotes from multiple suppliers.
The calculator multiplies thickness, width, and length together, divides by 12 to get board feet per piece, then scales by quantity and price to produce a final order total. This is the same calculation lumber yards use internally, so the result should match what you'd see on a supplier's quote. If your project also involves a rough log before milling, the Log Weight Calculator helps estimate handling weight before it reaches the sawmill.
How to use this Lumber calculator
- Enter the Thickness of a single board in inches (e.g., 2 for a nominal 2-inch board).
- Enter the Width in inches (e.g., 6 for a nominal 6-inch board).
- Enter the Length in feet for a single piece.
- Set the Quantity to the total number of pieces in your order.
- Enter the Price per Board Foot quoted by your supplier, using the "$" prefix field.
- Review the Total Cost result, shown as the highlighted primary output, along with Total Board Feet for verification against a supplier quote.
Formula & Methodology
The calculator uses the standard US board foot formula: board_feet_per_piece = (thickness × width × length) ÷ 12 total_board_feet = board_feet_per_piece × quantity total_cost = total_board_feet × price_per_board_foot Wherethicknessandwidthare in inches,lengthis in feet, andprice_per_board_footis in dollars. Worked example: 10 pieces of 2 in × 6 in × 10 ft lumber at $3.50 per board foot. - board_feet_per_piece = (2 × 6 × 10) ÷ 12 = 10 bd ft - total_board_feet = 10 × 10 = 100 bd ft - total_cost = 100 × $3.50 = $350.00
Frequently Asked Questions
A board foot is the standard unit of lumber volume in the US, equal to a piece of wood 1 inch thick, 12 inches wide, and 12 inches long. The calculator finds board feet per piece by multiplying thickness, width, and length together (in inches and feet) and dividing by 12, then multiplying by the number of pieces ordered. It's the unit most sawmills and lumber yards use for pricing rough and dimensional lumber.
Multiply the total board feet in your order by the price per board foot quoted by your supplier. The Lumber Calculator does this automatically once you enter thickness, width, length, quantity, and price per board foot, returning both the total board feet and total cost. This lets you compare quotes from different suppliers on an apples-to-apples basis.
Square footage measures only the surface area of a piece of wood (length × width), ignoring thickness, and is typically used for flooring or paneling. Board footage includes thickness as a third dimension, making it the correct unit for pricing rough-sawn or dimensional lumber sold by volume. If you need surface area instead, use the [Square Footage Calculator](/square-footage-calculator/).
No, dimensional lumber sizes like 2x4 or 2x6 refer to nominal (pre-surfacing) dimensions, not actual finished size. A nominal 2x4 actually measures about 1.5 x 3.5 inches after milling, so for accurate board foot totals, measure and enter the actual thickness and width rather than the nominal label.
Using nominal dimensions (2 in × 6 in × 10 ft) ÷ 12 = 10 board feet per piece. If you're working from actual surfaced dimensions (1.5 in × 5.5 in), the true board footage is closer to 6.875 board feet. Always check with your supplier whether their pricing uses nominal or actual dimensions.
Enter the thickness, width, and length of a single piece, then set the quantity to the total number of pieces in your order. The calculator multiplies board feet per piece by quantity to give you the total board footage and total cost in one step, which is useful for framing lumber, decking, or custom millwork orders.
Price per board foot depends on species, grade, moisture content (kiln-dried vs. green), and current market demand. Softwoods like pine and fir are typically cheaper than hardwoods like oak or maple, and prices fluctuate seasonally with construction demand and supply chain conditions. Always confirm current pricing with your local supplier before finalizing a budget.
Yes, as long as you enter the actual thickness and width of the lumber as measured, the formula works for both rough-cut and surfaced (S4S) boards. Rough-cut lumber typically has more material and yields a slightly higher board foot count than the same nominal size in surfaced form.
Linear feet measures only length, regardless of width or thickness, and is common for trim, molding, or fencing priced by the running foot. Board feet accounts for all three dimensions and is the standard for lumber sold by volume, such as framing studs, beams, and hardwood boards.
Total lumber needed depends on your framing layout, stud spacing, and project size, which is typically calculated separately using a framing plan or lumber takeoff. Once you know the piece count, dimensions, and species for each type of lumber, run each group through this calculator to get total board feet and cost for your material order.
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