The Board Feet of Common Lumber Dimensions


Lumber is most often measured in board feet, especially in forestry and milling. Whether you are a sawmill operator wondering how many boards you can get out of a tree or a carpenter tallying up board feet for a project, it can be helpful to know exactly how many board feet are in individual boards. Have no fear: We have you covered! In this article we will map out common lumber dimensions and the board feet in each.

What is a Board Foot?

In forestry, sawmilling, and lumber, “board feet” is a standard unit of measurement that describes a hypothetical green (undried) and rough (unplaned) board of wood measuring 12″x12″x1″. when boards are still on the stump or in a log, this is a measurement of likely yield of the tree or log post-milling. In lumber, however, it is a measurement of gross volume prior to drying and planing.

Below is a representation of exactly one board foot.

The number of board feet in each board depends on these theoretical boards as a unit of yield.

In larger quantities, board feet may be expressed as “MBF” for “thousand board feet.” If you are interested in learning more about board feet and MBF, we have an article on the subject here.

How to Calculate the Board Foot Volume of a Board

Calculating how many board feet are in a single piece of lumber is a simple process. The Dimensions of each board are going to be written as WxHxL, where the width and height are in inches and the length is an feet. For example, an 8-foot 2×4 will be written as 2″x4″x8′. Simply multiply these numbers together and divide by 12. The formula is shown below:

(W”xH”xL’)/12

How Many Board Feet Are in a 2×4?

2x4s are one of the most common dimensions used in lumber. Used for internal studs and a great variety of structural uses and small projects, they are a mainstay of carpentry work and one of the most in-demand products of sawmills. Below is a table of various lengths of 2×4 boards and the board feet in a single piece of each length.

LengthBoard Feet
8′5.33
10′6.67
12′8
14′9.33
16′10.67

How Many Board Feet Are in a 2×6?

2×6 boards are mostly used as framing lumber for walls, roofs, floors, and decks, and they are one of the most important dimensions in the softwood market. Below is a table of various lengths of 2×6 boards and the board feet in a single piece of each length.

LengthBoard Feet
8′8
10′10
12′12
14′14
16′16

How Many Board Feet Are in a 2×8?

2×8 boards are less common, but still used as framing applications where more insulation or more structure is desired. Below is a table of various lengths of 2×8 boards and the board feet in a single piece of each length.

LengthBoard Feet
8′10.67
10′13.33
12′16
14′18.67
16′21.33

How Many Board Feet Are in a 1×3?

1×3 boards, also known as furring strips, are often used to create a level plane and surface on which to attach walls and ceilings. Below is a table of various lengths of 1×3 boards and the board feet in a single piece of each length.

LengthBoard Feet
8′2
10′2.5
12′3
14′3.5
16′4

How Many Board Feet Are in a 1×4?

1x4s, along with the rest of the one-inch-thick dimensions, are often used for surfaces, such as walls, floors, and ceilings. Below is a table of various lengths of 1×4 boards and the board feet in a single piece of each length.

LengthBoard Feet
8′2.67
10′3.33
12′4
14′4.67
16′5.33

How Many Board Feet Are in a 1×6

1×6 pieces of lumber are incredibly common and one of the most popular dimensions of 1-inch thick lumber. Used for walls, ceilings, floors, and other surfaces, 1x6s are a popular product with sawmills everywhere. Below is a table of various lengths of 1×6 boards and the board feet in a single piece of each length.

LengthBoard Feet
8′4
10′5
12′6
14′7
16′8

How Many Board Feet Are in a 1×8?

1x8s are less common but still used for applications where wider boards are nice aesthetically, such as flooring and staircases. Below is a table of various lengths of 1×8 boards and the board feet in a single piece of each length.

LengthBoard Feet
8′5.33
10′6.67
12′8
14′9.33
16′10.67

How Many Board Feet are in a 4×4?

4x4s are a more utilitarian cut of lumber used largely for legs, posts, and other supports. They are perfect for decks, sheds, chicken coops, and other outdoor projects. Below is a table of various lengths of 4×4 boards and the board feet in a single piece of each length.

LengthBoard Feet
8′10.67
10′13.33
12′16
14′18.67
16′21.33

How Many Pieces of lumber Are in One MBF?

With these charts, it is easy to calculate how many pieces of lumber are in one MBF (one thousand board feet). Divide 1000 by the board feet in the dimensions you wish to use. For example, if you are looking to find the number of 8 foot 2x4s in one MBF, divide 1000 by 5.33, and you will get an answer of 187 pieces of lumber (with a small remainder).

The Difference Between Actual and Nominal Dimensions.

One should remember when reviewing this information the difference between nominal and actual volumes. A standard 2×4 will have smaller dimensions than the nominal “2×4” label because board feet measures green, unplaned lumber, both of which reduce the net volume of the boards. However, these processes will not reduce the board feet in each dimension because it references the rough, pre-processed state of the board–At least in theory. While this distinction should not be overly impactful to your calculations, it can be helpful to keep in mind.

Zachary Lowry

Professionally trained as a forester, I spent my early career working for large timberland owners in northern Maine, managing forest land and investments in the form of managing timber harvest operations as well as planning and managing precommercial thinning, planting, and herbicide application programs. These days I work on my own land and help timberland owners large and small manage theirs.

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