Free Contractor Tool
Board Foot Calculator
Enter thickness, width, length, and quantity for each lumber size to instantly get total board feet. Add as many sizes as your order needs, then enter a price per board foot to see your total lumber cost.
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Calculate Board Feet
Enter the thickness, width, length, and quantity for each lumber size. Add a row for every size on your order and the calculator totals the board feet for you. Results update instantly.
Enter your supplier’s board-foot rate to get total lumber cost.
Results
Total board feet
53.33
Total pieces
10
Board feet / piece
5.33
Total cost
Enter price above
Nominal vs Actual Lumber Dimensions
Dimensional lumber is sold by its nominal call size, but the finished board is smaller after milling and drying. Board feet for pricing are figured from nominal dimensions, so enter nominal thickness and width in the calculator above.
How to calculate board feet
A board foot is 144 cubic inches of lumber — the volume of a board 1" thick, 12" wide, and 12" long. The full formula is thickness (in) × width (in) × length (in) ÷ 144.
Because lumber length is almost always quoted in feet, the practical formula is thickness (in) × width (in) × length (ft) ÷ 12. Multiply by the number of pieces for the order total.
Example: a 2×4 that is 8 feet long is (2 × 4 × 8) ÷ 12 = 5.33 board feet per piece. Ten of them is 53.3 board feet.
Nominal vs actual: which to use
A 2×4 does not actually measure 2" × 4" — the finished board is 1.5" × 3.5" after it is planed and dried. The larger “nominal” number is the call size the mill starts from.
For pricing and ordering, board feet are figured from nominal dimensions, so a 2×4×8 is billed at 5.33 board feet even though its true volume is smaller. Only use actual dimensions when you need the true finished volume for a specialty or hardwood job.
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Common Questions About Board Feet
How do you calculate board feet?
Board feet = (thickness in inches × width in inches × length in inches) ÷ 144. Since lumber length is usually given in feet, the practical formula is (thickness in inches × width in inches × length in feet) ÷ 12. Multiply by the number of pieces for the order total. This calculator does the math for every row automatically.
What is a board foot?
A board foot is a unit of lumber volume equal to 144 cubic inches — the wood in a board 1" thick, 12" wide, and 12" long (1" × 12" × 12" = 144 cubic inches). It is the standard unit for pricing rough and dimensional lumber and is not the same as a linear foot or a square foot.
Do you use nominal or actual dimensions for board feet?
Use nominal dimensions for board feet when pricing. A 2×4 is figured as 2" × 4" even though the finished board actually measures 1.5" × 3.5". Lumber is sold by its nominal call size, so nominal dimensions give the board-foot count your supplier bills from.
How many board feet are in a 2x4x8?
A 2×4 that is 8 feet long contains 5.33 board feet using nominal dimensions: (2 × 4 × 8) ÷ 12 = 64 ÷ 12 = 5.33 board feet per piece. Ten pieces would be 53.3 board feet.
How is a board foot different from a linear foot?
A linear (running) foot measures only length, regardless of thickness or width. A board foot measures volume, factoring in thickness and width too. A 2×12 holds three times the board feet of a 2×4 of the same length. Use linear feet for run-based trim and framing takeoffs, and board feet for volume-based lumber pricing.
How do I price lumber by the board foot?
Multiply the total board feet by the price per board foot from your supplier — for example, 200 board feet at $4.50 equals $900. Calculate board feet for every size on the order, since each dimension has a different count. Use the optional price field in this calculator to get your total lumber cost instantly.
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Book a Free DemoBoard-foot calculations use nominal lumber dimensions for pricing per standard U.S. lumber grading practice. Actual (dressed) dimensions are smaller. Verify sizes and unit pricing against your supplier’s quote before ordering.