Use rough dimensions
Calculate board feet from the stock you need to buy before milling, not only from the final part size. Flattening, jointing, defects, and grain selection all affect what the project really consumes.
Use the formula consistently
For stock measured in inches and feet, multiply thickness in inches by width in inches by length in feet, then divide by 12. Multiply the result by the current price per board foot.
Add an allowance for usable yield
The formula gives volume, not a promise that every inch becomes a part. Add a documented waste allowance for defects, milling loss, matching, and cutoffs.
Shop 101
Turn this guide into a tested shop decision.
You leave with one documented input, one controlled result, and one clearer next action.
- Name the material, dimension, or cost input that affects the decision.
- Use the guide and calculator to make the assumption visible.
- Test or compare the result before committing final material, time, or client scope.
Related tools & lessons
Common questions
What is one board foot?
One board foot is a volume equal to a board 1 inch thick, 12 inches wide, and 1 foot long.
What is the board foot formula?
Thickness in inches × width in inches × length in feet ÷ 12 = board feet.
Does board-foot pricing include waste?
No. It measures lumber volume. Add your own allowance for the yield and quality requirements of the project.