Board Feet Calculator
Convert lumber dimensions into board feet (the standard unit for pricing rough timber) for any quantity, with the total material cost. Calculates in your browser.
Total board feet
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Show the math
A board foot is 144 cubic inches of lumber:
board feet = thickness(in) × width(in) × length(ft) ÷ 12
total = board feet × quantity
Rough-sawn lumber is usually priced on nominal (full) dimensions; surfaced lumber is smaller. Enter the dimensions your supplier prices on. All math runs locally in your browser.
What this does
A board feet calculator converts lumber dimensions into board feet (the standard unit for pricing rough timber) for any quantity, with the total cost.
How to use it
- Enter the thickness, width, and length.
- Enter the quantity.
- Enter a price per board foot.
- Read the board feet and cost.
How it works
One board foot is 144 cubic inches. Use nominal thickness for rough-sawn stock; surfaced lumber is smaller.
board feet = T(in) × W(in) × L(ft) ÷ 12
Understanding your result
Board feet is the pricing unit for rough timber, so it is what a lumberyard quote is built on. Use nominal dimensions for rough-sawn stock, but remember surfaced (S4S) boards are actually smaller than their nominal size, so a planed board yields fewer usable inches. Add a margin for defects, knots, and saw cuts on top of the bare requirement.
Example
A 2-inch by 6-inch board 8 ft long is 8 board feet.
Sources & methodology
Last updated .
Frequently asked questions
What is a board foot?
One board foot is 144 cubic inches, a piece 1 inch thick, 12 inches wide, and 1 foot long. It is the standard volume unit for hardwood lumber.
How is it calculated?
Board feet = thickness (in) × width (in) × length (ft) ÷ 12, multiplied by the quantity. Use nominal thickness for rough-sawn stock.
Nominal or actual size?
Rough lumber is usually priced on nominal (full) dimensions; surfaced lumber is smaller. Enter the dimensions your supplier prices on.
Do you store my numbers?
No. Everything is calculated locally in your browser.
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