Board Foot Calculator – Measure Lumber Volume Instantly
A board foot calculator helps woodworkers, contractors, and lumber buyers determine the volume of lumber in board feet. One board foot equals a piece of wood 1 inch thick, 12 inches wide, and 12 inches long (144 cubic inches). Use this tool to instantly calculate how much lumber you need and estimate your material costs.
Enter the thickness of the board in inches.
Enter the width of the board in inches.
Choose whether you are entering length in feet or inches.
Enter the length of the board in your selected unit.
How many boards of this size do you need?
Enter the cost per board foot to calculate total material cost.
Your results will appear here
How to Use This Calculator
1. Enter the thickness of your board in inches. 2. Enter the width of your board in inches. 3. Select whether your length measurement is in feet or inches, then enter the length. 4. Enter the number of boards you need. 5. Optionally, enter the price per board foot to get a total cost estimate. 6. Your results — board feet per board, total board feet, and estimated cost — will appear instantly below.
What Is a Board Foot?
A board foot (BF) is the standard unit of measurement for lumber volume in North America. It represents a piece of wood that is 1 inch thick, 12 inches wide, and 12 inches long — equivalent to 144 cubic inches or 1/12 of a cubic foot.
Board Foot Formula
The formula to calculate board feet is:
Board Feet = (Thickness (in) × Width (in) × Length (in)) ÷ 144
Or equivalently, when length is in feet:
Board Feet = (Thickness (in) × Width (in) × Length (ft)) ÷ 12
Example Calculation
For a board that is 1.5 inches thick, 6 inches wide, and 8 feet long:
- Board Feet = (1.5 × 6 × 8) ÷ 12 = 72 ÷ 12 = 6 BF
Why Board Feet Matter
Lumber is typically sold and priced by the board foot, especially for hardwoods. Knowing the board footage of your project helps you:
- Order the correct amount of lumber without waste or shortage
- Compare prices between suppliers accurately
- Budget your woodworking or construction project
- Estimate shipping or transport costs for large orders
Rough vs. Surfaced Lumber
Keep in mind that board feet are usually measured on rough (unsurfaced) lumber dimensions. After milling and surfacing, the actual dimensions will be smaller — a "1-inch" board from a lumber yard is typically 3/4 inch after surfacing. Always use the nominal (rough) dimensions when purchasing lumber by the board foot.