Board Foot Calculator
A board foot calculator finds the volume of lumber in board feet, the unit hardwood is sold in. One board foot equals 144 cubic inches, calculated as thickness (inches) times width (inches) times length (feet), divided by 12. Enter your board dimensions and quantity below to get the total board feet.
board feet = (thickness_in x width_in x length_ft / 12) x quantity; optional price per board foot.
- Per board
- 0 bf
- Total boards
- 1
Enter thickness, width, length and quantity to see the board feet.
Estimate only. Densities, yields and prices vary by supplier, moisture and region; confirm before ordering.
How Do You Calculate Board Feet?
To calculate board feet, multiply the board's thickness in inches by its width in inches by its length in feet, then divide by 12. A board 1 inch thick, 6 inches wide and 8 feet long is 1 times 6 times 8 divided by 12, which is 4 board feet. Multiply by the number of identical boards for the total. The calculator does this and can estimate cost from a price per board foot.
What Is a Board Foot?
A board foot is a unit of lumber volume equal to 144 cubic inches, the volume of a board 1 foot long, 1 foot wide and 1 inch thick. Hardwood lumber is priced per board foot rather than by length, because it accounts for thickness and width together. This is why furniture makers and woodworkers estimate in board feet, which the calculator provides from your board dimensions.
How Do You Estimate Lumber Cost in Board Feet?
To estimate lumber cost, calculate the total board feet, then multiply by the price per board foot from your supplier. Hardwood species vary widely in price per board foot, so enter your local price for an accurate figure. The calculator combines the volume and cost steps, and remember that thicker rough stock is measured before planing, which affects the usable yield.
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How Do You Calculate Board Feet?
Formula
Board Feet = Thickness (in) x Width (in) x Length (ft) / 12
- Measure the board thickness and width in inches, and the length in feet.
- Multiply thickness by width by length.
- Divide by 12 to get board feet (or, if all three dimensions are in inches, divide by 144).
- Multiply by the number of identical boards for the total.
Worked example
A 1 inch thick, 6 inch wide, 8 foot long board is 1 x 6 x 8 / 12 = 4 board feet. A 2x4 stud 8 feet long is 2 x 4 x 8 / 12 = 5.33 board feet.
- Nominal vs actual: hardwood is priced on rough-sawn nominal sizes (a 4/4 board means 1 inch nominal thickness), but for surfaced store-bought lumber like a 2x4, use the actual dry dimensions (1.5 in x 3.5 in) for the true volume.
- A board foot is a volume of 144 cubic inches, equal to a board 1 foot by 1 foot by 1 inch.
- Add 10 to 25 percent to your board foot total for saw kerf waste, grain matching and milling.
Frequently asked questions
- How do I calculate board feet?
- Multiply thickness in inches by width in inches by length in feet, then divide by 12. A 1 inch by 6 inch by 8 foot board is 4 board feet.
- What is a board foot?
- A board foot is a lumber volume unit equal to 144 cubic inches, the volume of a 1 foot by 1 foot by 1 inch board.
- How is lumber priced by board foot?
- Hardwood is priced per board foot, which accounts for thickness and width together. Multiply your total board feet by the price per board foot.
- Why are board feet divided by 144?
- When all three dimensions are in inches, you divide by 144 because a board foot is 144 cubic inches (12 x 12 x 1). If you measure length in feet instead, you divide by 12.
- How many board feet is a 2x4x8?
- Using nominal dimensions: 2 x 4 x 8 / 12 = 5.33 board feet. Using the actual surfaced size of 1.5 by 3.5 inches: 1.5 x 3.5 x 8 / 12 = 3.5 board feet.