Board Foot Calculator
Find the board footage of lumber by entering your boards’ length, width, and thickness. Add the price per board foot to estimate the cost.
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The calculator above will easily calculate the board footage and convert dimensions automatically. It will also help calculate the price of the board or the total lumber price for multiple boards.
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.
What is a Board Foot?
A board foot, abbreviated bd ft, is a unit of measurement for the volume of a piece of wood in feet. Large slabs of rough wood, hardwood lumber, and exotic woods are usually measured and priced by the board foot, which accounts for the thickness, width, and length of the lumber.
One board foot is equal to 144 cubic inches, and is equivalent to a 1-inch thick board that is 1 square foot in size. A board foot is abbreviated bd ft, 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.
Unlike 2x4s and dimensional lumber, which are measured using nominal measurements, 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.
BF = 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.
BF = Thickness [in] × Width [in] × Length [ft] / 12
How to Calculate the Board Footage of a Log
There are a few methods that you can use to find the total lumber in a log, but the most common method is to use a Doyle log scale.
To use a Doyle log scale, start by measuring the length of the log in feet and the smallest diameter of the log inside the bark in inches.
Then, refer to the Doyle log scale linked above to find the total number of board feet in the log.
There are several other commonly used scales for measuring logs and standing trees, including the International 1/4-inch scale and the Scribner standing tree scale.
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)
|4′ L||6′ L||8′ L||10′ L||12′ L||14′ L|
|4″ W||1.33 BF||2.0 BF||2.67 BF||3.33 BF||4.0 BF||4.67 BF|
|6″ W||2.0 BF||3.0 BF||4.0 BF||5.0 BF||6.0 BF||7.0 BF|
|8″ W||2.67 BF||4.0 BF||5.33 BF||6.67 BF||8.0 BF||9.33 BF|
|10″ W||3.33 BF||5.0 BF||6.67 BF||8.33 BF||10.0 BF||11.67 BF|
|12″ W||4.0 BF||6.0 BF||8.0 BF||10.0 BF||12.0 BF||14.0 BF|
8/4 Lumber (2″ Thick)
|4′ L||6′ L||8′ L||10′ L||12′ L||14′ L|
|4″ W||2.67 BF||4.0 BF||5.33 BF||6.67 BF||8.0 BF||9.33 BF|
|6″ W||4.0 BF||6.0 BF||8.0 BF||10.0 BF||12.0 BF||14.0 BF|
|8″ W||5.33 BF||8.0 BF||10.67 BF||13.33 BF||16.0 BF||18.67 BF|
|10″ W||6.67 BF||10.0 BF||13.33 BF||16.67 BF||20.0 BF||23.33 BF|
|12″ W||8.0 BF||12.0 BF||16.0 BF||20.0 BF||24.0 BF||28.0 BF|
- Nebraska Forest Service, Tree and Log Scale, https://nfs.unl.edu/documents/ruralforestry/tree%20and%20log%20scale%20Doyle%20WEB.pdf