Pricing out a stack of lumber by hand means juggling three dimensions, a conversion factor, and whatever units your supplier happens to use. A board foot calculator removes that friction: enter the thickness, width, and length of a board, pick your units, and get the total board feet and cost in one step instead of running the math on paper for every piece.
How to use this board foot calculator
- Enter the Number of Boards you’re buying or measuring, since most orders involve more than one identical piece.
- Enter the Thickness and choose its unit from the dropdown (millimeters, centimeters, meters, inches, or feet).
- Enter the Width and choose its unit from the same list of options.
- Enter the Length and choose its unit, which adds two extra choices beyond the others: feet/inches and meters/centimeters, for boards measured in mixed units.
- Optionally, use the Common Nominal Sizes quick-fill dropdown to load a standard lumber size such as 2×4, 2×6, 2×8, 2×10, or 2×12 instead of typing dimensions manually.
- Enter the Price and select a currency from the dropdown, or choose “Add Custom” if your currency isn’t listed.
- Click Calculate to see the Total Board Feet, the board feet Per Board, and the Total Cost.
- Use Save as Image or Download PDF to keep a record of the result, or click Clear All to start over with a new board.
What this board foot calculator does
The tool takes the three physical dimensions of a board, thickness, width, and length, along with a quantity, and converts them into a single volume measurement called a board foot. It then multiplies that volume by your price input to show what the order actually costs. Because the thickness, width, and length fields each carry their own unit dropdown, you can mix metric and imperial entries on the same board without converting anything yourself first. The currency dropdown does the same job for pricing, covering more than two dozen currencies plus a custom option.
The board foot formula and how it’s applied
A board foot is a unit of lumber volume, not a unit of length. One board foot equals a square foot of lumber that’s one inch thick, which works out to 144 cubic inches, or 1/12 of a cubic foot. The calculator applies the standard formula to every board you describe, then multiplies by the quantity you entered.
Board Feet = (Thickness in inches x Width in inches x Length in feet) / 12
That single-board figure is then multiplied by the Number of Boards field to produce the Total Board Feet result, and multiplied again by your entered price to produce the Total Cost. The “Per Board” output shows the volume of one piece on its own, which is useful when you’re comparing prices across suppliers who quote per board foot rather than per order.
Why unit flexibility matters
Lumber dimensions get quoted differently depending on the supplier and the region. A yard might list thickness in inches but length in feet and inches together, or a metric supplier might give every dimension in millimeters. Because each dimension in this board foot calculator has its own independent unit setting, you don’t have to pre-convert anything on a separate sheet before entering numbers.
Using the nominal size shortcut
The Common Nominal Sizes dropdown fills in standard framing lumber dimensions automatically, which saves a step when you’re pricing common stock rather than a custom cut.
| Nominal Size Option |
Typical Use |
| Custom size |
Manual entry of thickness, width, and length |
| 2×2 |
Furring strips, small framing |
| 2×4 |
Wall studs, general framing |
| 2×6 |
Joists, heavier framing |
| 2×8 |
Larger joists and beams |
| 2×10 |
Long-span joists and headers |
| 2×12 |
Beams and stair stringers |
Wrapping up
This board foot calculator turns three dimensions and a price into a straightforward cost figure, whether you’re buying a single custom-cut board or a full order of identical framing lumber. Keep in mind that the result is an estimate. Actual dressed lumber dimensions and supplier pricing can vary, so it’s worth confirming both with your lumber yard before finalizing an order, especially on larger purchases where small rounding differences add up.
Frequently asked questions
What exactly is a board foot?
A board foot is a unit of lumber volume equal to a piece one foot long, one foot wide, and one inch thick. That works out to 144 cubic inches, or one-twelfth of a cubic foot. It’s different from a linear foot, which only measures length and ignores thickness and width entirely.
Can I mix inches and feet when entering dimensions?
Yes. The length field includes a feet/inches option alongside plain inches, feet, and the metric choices, so you can enter a board that’s, for example, six feet four inches long without converting it to a decimal first.
Does the calculator handle multiple boards at once?
It handles one board type at a time, but the Number of Boards field lets you multiply that single board’s dimensions by however many identical pieces you’re buying, so a full stack of matching lumber only takes one entry.
Why does the result show board feet instead of just cost?
Board feet is the standard unit lumber is priced by, so seeing Total Board Feet, Per Board, and Total Cost together lets you compare the calculator’s output directly against a supplier’s quoted price per board foot, rather than trusting a single dollar figure with no way to check the math behind it.
