Board Foot Calculator

How to Use Our Board Foot Calculator

Our tool is designed to be both straightforward and flexible:

Enter Dimensions: Input the thickness, width, and length of the lumber. You can conveniently switch between various units like millimeters, centimeters, meters, inches, and feet. For length, we even support compound units like feet & inches or meters & centimeters!
Specify Quantity: Indicate the number of lumber pieces you have.
Calculate Board Feet: The calculator will instantly show you the total volume in board feet.
Estimate Cost: To find the cost, simply enter the price per board foot into our price calculator for an instant total cost estimation.

What Is a Board Foot?

A board foot (BF or BFT) is a unit of measurement for the volume of lumber in the United States and Canada. It represents the volume of a board that is one foot long, one foot wide, and one inch thick.

It's a nominal measurement, meaning it refers to the size of the wood before it's planed and dried. So, even though a board's actual dimensions might be slightly smaller after processing, its board-foot volume is calculated based on its original, rough-sawn dimensions.

The Board Foot Formula

The calculation is quite simple. The formula to determine board feet is:

\text{Board Feet (BF)} = \frac{\text{Thickness (in)} \times \text{Width (in)} \times \text{Length (ft)}}{12}

Alternatively, if all dimensions are in inches:

\text{Board Feet (BF)} = \frac{\text{Thickness (in)} \times \text{Width (in)} \times \text{Length (in)}}{144}

Example: Let's say you have a board that is 2 inches thick, 6 inches wide, and 8 feet long.

\text{Board Feet} = \frac{2 \text{ in} \times 6 \text{ in} \times 8 \text{ ft}}{12} = \frac{96}{12} = 8 \text{ BF}

If you have 10 such boards, the total volume is $8 \text{ BF} \times 10 = 80 \text{ BF}$ . If the price per board foot is $12, the total cost would be $80 \times 12 = 960$ dollars.

Frequently Asked Questions (FAQ)

What's the difference between a board foot and a linear foot?

A linear foot measures only length, whereas a board foot measures volume (length, width, and thickness). A board that is 12 linear feet long tells you nothing about its thickness or width. A board foot accounts for all three dimensions, making it a more accurate measure of the total amount of wood.

Why divide by 144?

The division by 144 in the formula (when length is measured in inches) comes from converting cubic inches to board feet. One board foot is equivalent to the volume of 1 ft × 1 ft × 1 in, which is $12 \text{ inches} \times 12 \text{ inches} \times 1 \text{ inch} = 144 \text{ cubic inches}$ . So, dividing the total cubic inch volume by 144 converts it into board feet.

What are nominal vs. actual dimensions?

Nominal dimensions are the size of the rough lumber before it's dried and planed (e.g., a "2x4"). Actual dimensions are the final measurements after processing, which are smaller (a typical 2x4 is actually about 1.5" x 3.5"). Board foot calculations traditionally use the nominal dimensions. Always clarify with your lumber supplier which measurements are being used.

How do I calculate the cost of lumber?

To calculate the cost, simply multiply the total board feet by the price per board foot. Our tool includes a built-in price calculator to make this easy for you.

\text{Total Cost} = \text{Total Board Feet} \times \text{Price per Board Foot}

Does this calculation apply to all types of wood?

Yes, the board foot calculation is a standardized volume measurement and applies to any wood species, whether it's oak, pine, maple, or any other type. However, the price per board foot will vary significantly between different species and grades of lumber.

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