Board Foot (Lumber) Calculator
Calculate board feet for hardwood and lumber from thickness, width, length and quantity — and the cost at a price per board foot.
How to use
- 1Enter the thickness and width (inches) and length (feet).
- 2Enter the number of boards and the price per board foot.
How it's calculated
Board feet = thickness (in) × width (in) × length (ft) ÷ 12. One board foot = 144 cubic inches.
Frequently asked questions
Do I use nominal or actual size?
Hardwood is usually sold by rough (nominal) thickness in quarters — 4/4 = 1 in, 8/4 = 2 in. Use the size the seller prices by.
What does 4/4 mean?
Four quarters of an inch, i.e. 1 inch rough thickness. 5/4 is 1¼ in, 8/4 is 2 in.
How is construction lumber sold?
Usually by the piece or linear foot (e.g. a 2×4×8), not by the board foot.