A board foot is a volume of wood 1" thick, 12" wide and 12" long — 144 cubic inches. Hardwood and many lumber yards price by the board foot, so knowing the count lets you compare prices and estimate a project.
Formula
Board feet = thickness (in) × width (in) × length (ft) ÷ 12. Ten 2×6 boards 8 ft long: 2 × 6 × 8 ÷ 12 × 10 = 80 board feet.
One cubic metre equals about 423.8 board feet.
Watch: how it is done
Video by The Organic Chemistry Tutor on YouTube. More in our video library.
Frequently asked questions
Do I use nominal or actual size?
For rough hardwood, use the nominal thickness (4/4, 8/4). Many yards also price dimensional softwood on nominal sizes. Check how your supplier quotes.
What does 4/4 mean?
Quarter-inch notation: 4/4 is 1" rough, 5/4 is 1-1/4", 8/4 is 2".
Results are planning estimates. For structural work, confirm requirements with your local building authority and a qualified professional. See our disclaimer.