Lumber Board Feet Calculator
Convert board dimensions into board feet and a price estimate for any lumber order.
Results are estimates. Lumber yards may price from rough or nominal sizes — confirm how your supplier measures before ordering.
How to Calculate Board Feet
A board foot is the standard unit for buying lumber, especially hardwood.
Board dimensions
Enter the thickness and width in inches and the length in feet. The board-foot formula is thickness × width × length ÷ 12.
Quantity
Set how many identical boards you're buying. The calculator multiplies the board feet per piece by the quantity and applies your price.
Common Mistakes to Avoid
- Mixing units. Thickness and width are in inches, length is in feet — keep them straight.
- Nominal vs actual size. A "1 inch" board is often 3/4 inch finished; use the size your yard prices from.
- Forgetting waste. Buy extra for defects, knots, and cutting around them — board feet measure raw stock, not usable wood.
- Comparing price per piece. Boards of different sizes only compare fairly per board foot.
Frequently Asked Questions
A unit of lumber volume — 12 in wide, 12 in long, 1 in thick, or 144 cubic inches.
Thickness (in) × width (in) × length (ft) ÷ 12, then multiply by the number of pieces.
Use the size your yard prices from — often the rough or nominal dimension for hardwood.
From a couple of dollars for softwood to well over ten for premium hardwood. Enter your local price.
They let you price and compare lumber of any size on equal terms.