Board Foot Calculator – Lumber Board Feet

Enter the lumber dimensions you want to use and the number of pieces. Use nominal dimensions only when your estimating method calls for them; otherwise enter the actual measured dimensions.

Thickness

Width

Thickness & width unit

Length

Length unit

Number of pieces

Result

How to Use

Enter the thickness and width of one piece of lumber, then select the matching unit.
Enter the piece length and choose its unit. The length can be entered in feet, meters, inches, centimeters or millimeters.
Enter the number of identical pieces. The calculator multiplies the board-foot volume of one piece by this quantity.
Choose deliberately whether your estimate should use nominal lumber dimensions or actual dressed/measured dimensions. This calculator does not silently convert between them.
The result shows total board feet, board feet per piece and the equivalent cubic volume.

Formula

Board feet per piece: board_feet = thickness_in × width_in × length_in ÷ 144
Total board feet: total_board_feet = board_feet_per_piece × quantity

Worked Example

Ten pieces entered as 2 inches thick, 6 inches wide and 8 feet long.

Convert the length: 8 ft × 12 = 96 in.
One piece: 2 × 6 × 96 ÷ 144 = 8 board feet.
Ten pieces: 8 × 10 = 80 board feet.

Result: Total: 80 board feet

About This Tool

What this tool does

This calculator measures lumber volume in board feet. One board foot is exactly 144 cubic inches, equivalent to a volume 1 inch thick × 12 inches wide × 12 inches long.

When to use it

Use it when estimating hardwood, rough lumber, slabs or other lumber sold or tracked by board-foot volume, or when you need to convert a set of rectangular lumber dimensions into board feet.

What the result means

The total board-foot value is a volume measure, not a surface-area or linear-foot measure. The equivalent cubic-foot and cubic-meter values describe the same entered lumber volume in other units.

Assumptions & limitations

Each piece is treated as a rectangular solid with the exact dimensions you enter. The calculator does not decide whether nominal or actual lumber dimensions are appropriate, does not account for taper, live edges, kerf, surfacing losses or defect allowances, and does not estimate price unless a separate cost calculation is made.

Frequently Asked Questions

What is one board foot?

One board foot is a lumber volume of 144 cubic inches. A simple example is a piece 1 inch thick, 12 inches wide and 12 inches long.

What is the board-foot formula?

When all dimensions are in inches, multiply thickness × width × length and divide by 144. If length is in feet, the equivalent common form is thickness in inches × width in inches × length in feet ÷ 12.

Should I use nominal or actual lumber dimensions?

Use the dimensions required by your supplier, invoice, estimating method or project documentation. Nominal and actual dimensions can differ, so this calculator intentionally uses exactly what you enter rather than choosing for you.

Can I calculate board feet from metric dimensions?

Yes. Enter thickness and width in centimeters or millimeters and length in meters, centimeters or millimeters. The calculator converts the dimensions internally and returns board feet.

Does board feet tell me how many boards I need for a project?

Not by itself. Board feet measures lumber volume. Project quantity can also depend on board layout, cut lengths, spacing, defects and waste, which should be estimated separately for the job.