Board Foot Calculator
Multiply lumber thickness in inches by width in inches by length in feet, divide by 12, and multiply by quantity to get total board feet. It handles a single piece or a whole stack of identical boards.
What this calculator does
The Board Foot Calculator estimates your result instantly from the values you enter, using standard construction & home formulas. Multiply lumber thickness in inches by width in inches by length in feet, divide by 12, and multiply by quantity to get total board feet. It handles a single piece or a whole stack of identical boards. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate rather than a certified or official figure.
Result
About Board Foot Calculator
A board foot is a unit of lumber volume equal to a piece 1 inch thick, 12 inches wide, and 1 foot long. Because thickness and width are usually measured in inches while length is in feet, the standard shortcut is thickness × width × length ÷ 12.
This calculator applies that formula and then multiplies by the quantity you enter, so you can price or order several matching boards at once.
Formula & Mathematical Calculation
Board Feet = f(Thickness (in), Width (in), Length (ft), Quantity)
Calculated according to standard construction formulas implemented in the calculator core.
Calculation Example
For boards 2 in thick, 6 in wide, and 8 ft long, ordering 5 of them:
- Per board = 2 × 6 × 8 ÷ 12 = 8 board feet
- Total = 8 × 5 = 40 board feet
The tool displays Board Feet 40 bd ft and notes "5 boards total = 40 board feet".
Key Benefits
- Applies the standard thickness x width x length / 12 board-foot formula automatically
- Multiplies by quantity so a full order of identical boards is totaled at once
- Accepts inches for thickness and width and feet for length, matching how lumber is measured
- Free and runs in the browser with no sign-up
How to Use this Calculator
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Enter the thickness
Type the board thickness in inches into the Thickness (in) field, such as 2. -
Enter the width
Type the board width in inches into the Width (in) field, such as 6. -
Enter the length
Type the board length in feet into the Length (ft) field, such as 8. -
Enter the quantity and calculate
Type how many identical boards you have in the Quantity field, then press Calculate to see the total Board Feet.
Assumptions & Limitations
What the calculation assumes
- Every value you enter is treated as an exact, known amount.
- Any rate or interval you enter is assumed to hold for the whole period unless the form asks for it separately.
- Results use standard published formulas and account only for the values entered above.
- Rounding is applied for display; the underlying calculation uses your full precision.
- Results are returned in the same units you enter, unless the tool states the output unit.
What it does not cover
- Board Foot Calculator produces a calculated result for reference and learning, not a certified or official measurement.
- Real-world outcomes differ when tolerances, rounding rules or local standards apply.
- Definitions and standards vary by region and change over time; verify the convention that applies to your case.
- Figures are only as accurate as the inputs you supply — check them before acting on the result.
- For work where the result carries real consequences, confirm it against an authoritative source.
Frequently Asked Questions
Free to use, no account needed. Calculations run in your browser, so nothing you type is sent to a server. Results are estimates — how we build and check our calculators.