Board Foot Calculator – How to Calculate Board Feet

Find the board footage of lumber by entering your boards’ length, width, and thickness. Add the price per board foot to estimate the cost.

What is a Board Foot?

A board foot, abbreviated bd ft, is a volume measurement of a piece of wood in feet. Large slabs of rough wood, lumber, and exotic woods are usually measured and priced by the board foot, which accounts for the thickness, width, and length of the lumber.

A board that is 1 inch thick × 1 foot wide × 1 foot long is 1 board foot. A board-foot is abbreviated BDFT, BF, or FBM(foot, board measure).

Board footage is used to quantify how much wood a board contains since length by itself is not enough to quantify how much volume the lumber contains. Boards that are wider or thicker contain more wood.

For example, a board that is ⁴/₄ × 4″ × 8′ has the same amount of wood as a board that is ⁴/₄ × 8″ × 4′. The board footage measurement indicates that both boards are equal in size, while using just the length measurement might make the thinner board appear larger.

Hardwood thickness is often measured in quarters of an inch, so you would refer to a 1″ board as four-quarters, expressed as ⁴/₄.

How to Calculate Board Feet

You can calculate board footage, which is the volume of wood the board contains, using the calculator above, or using a simple formula.

Using Length in Inches

You can calculate board feet by multiplying the board’s thickness in inches by the width in inches by the length in inches, and then divide the result by 144.

Thus, the formula to calculate board footage is (thickness × width × length) ÷ 144. Make sure you keep all measurements in inches, then divide by 144.

BDFT = Thickness [in] × Width [in] × Length [in] / 144

Using Length in Feet

You can also find the board footage of a board if your length dimension is in feet. Multiply the thickness of a board in inches by the width of the board in inches by the length of the board in feet, and then divide the result by 12.

BDFT = Thickness [in] × Width [in] × Length [ft] / 12

If you need help converting to inches, convert feet to inches, convert yards to inches, or convert centimeters to inches.

The calculator above will easily calculate the board footage and convert dimensions automatically. It will also help determine the price of the board given the price per BF.

This board foot calculator uses inches in decimal format or in quarters (e.g., 4/4). You can convert decimal measurements to fractions if you need the decimal equivalent for your dimensions.

Board Feet Charts

Refer to the charts below to quickly calculate the board feet for 4/4 and 8/4 stock.

4/4 Lumber (1″ Thick)

8/4 Lumber (2″ Thick)