Board Foot Calculator
Whether you are buying rough-sawn hardwood or estimating framing lumber, use our board foot calculator to instantly find the total volume and cost of your materials.
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Calculate Board Feet & Cost
Enter your lumber dimensions and quantities below. Add a price per board foot to estimate total project costs.
Board Foot Calculator
Calculate total board feet and cost for your lumber.
What Is a Board Foot?
A board foot is a specialized unit of volume used for lumber in the United States and Canada. Unlike linear feet, which only measure the length of a board, a board foot accounts for the width, thickness, and length of the wood.
By definition, one board foot is the equivalent of a piece of wood that is 12 inches wide, 1 foot (12 inches) long, and 1 inch thick. This equates to exactly 144 cubic inches. Hardwood lumber is almost always sold by the board foot because boards come in random widths and lengths, meaning standard pricing per linear foot wouldn't be accurate or fair.
How to Calculate Board Feet
Calculating board feet manually is simple once you know the standard formulas. There are two common ways to do the math, depending on the units you are measuring with:
- Using Inches: (Thickness × Width × Length) ÷ 144 = Board Feet
- Using Feet for Length: (Thickness in inches × Width in inches × Length in feet) ÷ 12 = Board Feet
For example, if you are buying an 8/4 thick board (which is 2 inches thick) that is 6 inches wide and 10 feet long, your calculation would look like this:
(2" × 6" × 10') ÷ 12 = 10 Board Feet.
Board Feet vs Linear Feet vs Square Feet
Understanding the difference between these measurements is crucial when planning a project or visiting the lumber yard:
- Board Feet (BF): Measures the total volume of the wood. Used primarily for hardwoods and rough-sawn lumber.
- Linear Feet (LF): Measures only the length of the board, ignoring thickness and width. Common for trim, molding, and standard dimensional softwood (like 2x4s) where the profile size is consistent.
- Square Feet (SqFt): Measures area (length × width), ignoring thickness. Often used for sheet goods like plywood, MDF, and flooring.
Worked Examples
Here are a few quick practical examples of calculating board feet for common scenarios:
- A standard 2x4: For a standard 2x4 that is 8 feet long. (2 × 4 × 8) ÷ 12 = 5.33 BF.
- A 2x6 framing stud: For a 2x6 that is 12 feet long. (2 × 6 × 12) ÷ 12 = 12 BF.
- A rough-sawn hardwood board: You pick out a piece of 4/4 walnut (1 inch thick) that is 7.5 inches wide and 9 feet long. (1 × 7.5 × 9) ÷ 12 = 5.625 BF.
Frequently Asked Questions
Take Your Woodworking Further
Stop guessing your cuts. After estimating your board feet, generate an optimized cut list to minimize your waste.
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