What is Board Foot?
A board foot is a unit of volume commonly used in the United States and Canada to measure lumber. In other words, it measures the amount of wood by volume, not length and width
It's equivalent to a piece of wood that is 1 foot long, 1 foot wide, and 1 inch thick. So, if you have a piece of wood that is 2 feet long, 6 inches wide, and 2 inches thick, that would be equal to 2 board feet. It's a handy way to quantify the amount of wood in a piece of lumber, especially when buying or selling. You could also check Board Foot in Wikipedia for further explains of board foot.
Remember, a board foot measures volume, so it takes into account length, width, and thickness, unlike a linear foot which only considers length.
How to Calculate Board Foot
Calculating board feet is relatively straightforward. The formula is:
Board Feet = Length (in feet) x Width (in feet) x Thickness (in inches)
...or
Board Feet = Length (in feet) x Width (in inches) x Thickness (in inches) / 12
...or
Board Feet = Length (in inches) x Width (in inches) x Thickness (in inches) / 144
...or
Board Feet = Square Feet x Thickness (in inches)
(Tips: 1 foot = 12 inches. 1 foot * 1 foot * 1 inch = 1 board foot. 1 foot * 1 foot = 1 square foot. 1 square foot * 1 inch = 1 board foot. )
Note: Buy More Lumber Than Board Feet Calculation
This formula assumes that the width and thickness are measured before the lumber is planed or sanded. If you're working with planed or sanded lumber, use the actual, not nominal, dimensions. So our suggestion is purchase a bit more lumber than calculations of our board feet calculator.
When embarking on a woodworking project, one of the key considerations is the amount of lumber needed. This is often calculated using the nominal dimensions of the lumber, the measurements before it has been planed or sanded. However, it's crucial to remember that the planing or sanding process can reduce the thickness of the wood, thereby affecting its overall volume. As such, when calculating the board feet using nominal dimensions, it's advisable to purchase a bit more lumber than the board feet calculation suggests. This ensures that you will have enough material to account for the reduction in size after planing or sanding. It's a practical approach that helps prevent running out of material mid-project, ensuring a smoother and more efficient woodworking experience.
If you're purchasing lumber and unsure about the measurements, don't hesitate to ask the seller. They should be able to provide you with the accurate dimensions.
Here's A Step-by-Step Guide for Board Feet Calculation:
-
Measure the Length and the Width: First, measure the length and the width of the wood in feet or in inches. If your measurement is in inches, divide it by 12 to convert it to feet.
-
Measure The Thickness: Next, measure thickness of the wood in inches or get it by asking the seller. It also expressed by "4/4" or "5/4", which are equal to 1 inch and 1.25 inches.
-
Calculate: Multiply the length (in feet) by the width and thickness (both in inches). Then, divide the result by 12 to get the total board feet. You could simply use our calculaor.
What "4/4" "5/4" "12/4" Means in Board Feet?
In the lumber industry, thickness is often expressed in quarters, a traditional method of measurement. Fractions like 4/4, 5/4, and 12/4 are read as "four quarters", "five quarters", and "twelve quarters" respectively. Each "quarter" signifies a quarter of an inch. Using this system, a piece of 4/4 wood would measure one inch thick, 5/4 wood would measure 1-1/4 inches thick, and 12/4 wood would be three inches thick.
This method of measurement is predominantly used for hardwoods and serves to standardize the thicknesses of different lumber pieces.
The Use of Board Foot
Board foot is used primarily in the lumber industry, specifically when buying, selling, or measuring wood. It's a standard unit of measure in North America for calculating the volume of lumber.
The concept of a board foot plays a pivotal role in the lumber industry, serving as a standard unit of measure in North America for quantifying the volume of wood. It's a term that's ubiquitous in the industry, with its applications spanning across various aspects of woodworking and lumber trade.
Here are a few scenarios where you might use board feet:
1. Purchasing Lumber:
When you're buying wood for a project, the price is often given in board feet. This helps standardize the cost across different sizes and types of lumber. This method of pricing provides a standardized approach that evens out the cost across diverse sizes and types of lumber, making it easier for consumers to understand exactly what they're paying for.
2. Estimating Material Needs:
If you're planning a woodworking project, you might calculate the board feet to determine how much wood you'll need. This can help you budget and ensure you have enough material. Calculating the board feet required for a project can aid in budgeting and ensuring the availability of sufficient material. It can prevent both the wastage of excess material and the inconvenience of a shortage.
3. Inventory Management:
For lumber yards or woodworking shops, board feet can be used to keep track of inventory. It's a more precise measure than simply counting the number of pieces, as it takes into account the length, width, and thickness of the wood. This ensures efficient inventory control and accurate record-keeping.
4. Selling Lumber:
Similarly, when selling lumber, prices are typically listed per board foot. This standard unit allows customers to easily compare prices between different types and sizes of wood, making their shopping experience more straightforward and transparent.
Key Terms Related to "Board Foot"
There are several terms related to "board foot" in the woodworking and lumber industry. Understanding these terms can help you navigate the world of woodworking and lumber purchasing with more confidence.
1. Linear Foot:
This term refers to the length of a board. If a board is sold by the linear foot, you're paying for it based on its length in feet, regardless of its width or thickness.
2. Square Foot:
This is a measure of area, calculated by multiplying the length (in Feet) and width (in Feet) of a board. If a board is 1 foot wide and 1 foot long, it is 1 square foot.
3. Cubic Foot:
This is a measure of volume like board feet, calculated by multiplying the length, width, and thickness of a board. If a board is 1 foot wide, 1 foot long, and 1 foot thick, it is 1 cubic foot. The difference between cubic foot and board feet is that cubic foot measures the thickness of the wood in feet while board feet measures the thickness in inches.
4. Rough Sawn:
This term refers to lumber that has been cut but not yet planed or sanded. It's typically somewhat larger than its nominal dimensions to allow for planing.
5. Planed or Surfaced:
This term refers to lumber that has been smoothed on one or more surfaces. Planed lumber is usually slightly smaller than its rough sawn dimensions due to material being removed in the planing process.
6. Kiln-Dried (KD):
This term refers to lumber that has been dried in a kiln to reduce its moisture content. Kiln-dried lumber is less likely to warp or twist.
7. Nominal Dimensions:
These are the dimensions of a piece of lumber before it is planed or dried. For example, a 2x4's nominal dimensions are 2 inches by 4 inches, but the actual dimensions will be slightly less.
8. Actual Dimensions:
These are the true dimensions of a piece of lumber after it has been planed and dried. For example, a 2x4's actual dimensions are typically 1.5 inches by 3.5 inches.
