Board 1
Decimals are supported for precise lumber sizing.
Board feet
0.00
Enter all three dimensions to calculate this row.
Est. row cost
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Free Lumber Tool
Free Board Feet Calculator
A board foot is a unit of lumber volume equal to 144 cubic inches, or a board that measures 12 inches by 12 inches by 1 inch. Use this free board feet calculator to estimate how much wood you need and what your lumber purchase may cost before you buy.
Board feet calculatorLumber calculatorWood board feet
Calculate your lumber volume
Add one board per row. Width and thickness stay in inches, and you can switch length between inches and feet.
Length Unit
How to calculate board feet
Use these steps when pricing hardwood, planning a project, or comparing lumber yard quotes.
Choose a length unit
Select whether you want to enter board length in inches or feet.
Enter your board dimensions
Type the length, width, and thickness for each board. Width and thickness stay in inches.
Add more boards as needed
Create extra rows for every board you want to include in the lumber total.
Review total board feet and cost
Check the running total, and optionally add a price per board foot to estimate material cost.
Board feet FAQ
Common questions from woodworkers, carpenters, and lumber buyers.
What is a board foot?
A board foot is a lumber measurement equal to 144 cubic inches. The standard example is a board that is 12 inches long, 12 inches wide, and 1 inch thick.
How do you calculate board feet?
When all dimensions are in inches, multiply length by width by thickness and divide by 144. If your length is in feet, convert it to inches first, or use this calculator to handle the conversion automatically.
Why does thickness matter in board foot calculations?
Board feet measures volume, not just surface area. Two boards with the same length and width will have different board footage if one is thicker than the other.
Can I estimate lumber cost with board feet?
Yes. If a mill or lumber yard quotes pricing by the board foot, multiply your total board feet by the price per board foot to estimate the material cost.
Should I use rough or finished thickness?
Use the thickness that matches how your lumber is sold. Rough lumber is often priced by rough dimensions, while surfaced lumber may be labeled and priced closer to finished thickness.