Work out the board feet of lumber and the total cost.
Calculated instantly in your browser.
How do you calculate board feet of lumber?
Board feet = thickness (in) × width (in) × length (in) ÷ 144, since one board foot equals 144 cubic inches. Use the nominal thickness and width. For example, five boards of 2 in × 6 in × 8 ft are 8 board feet each — 40 board feet, about 180 at 4.50 per board foot. Hardwood is usually priced by the board foot.
Understanding your result
Use the nominal thickness and width. Hardwood lumber is usually sold by the board foot, so this is handy for budgeting a project.
Formula and method
Board feet = thickness (in) × width (in) × length (in) ÷ 144. One board foot equals 144 cubic inches.
Assumptions and limitations
Board feet measure nominal volume, not the finished usable timber. Milling, planing, defects, offcuts and grain matching all reduce yield, so buy extra beyond the bare calculation. It uses the dimensions you enter and does not account for how boards are cut or how much waste your particular project will produce.
Worked example
Five boards of 2 in × 6 in × 8 ft are 8 board feet each — 40 board feet, about 180 at 4.50 per board foot.
How to use this tool
- Enter the thickness and width in inches.
- Enter the length and choose feet or inches.
- Add the quantity and an optional price, then press Calculate.
About the Board Feet Calculator
The Board Feet Calculator measures the volume of lumber in board feet — the standard way hardwood is priced — and totals the cost.
Who should use this tool
Woodworkers, furniture makers and DIYers buying hardwood, which is usually priced by the board foot. Useful for measuring a stack of boards, estimating a project's timber cost, and checking a lumber yard's total against your own figure before paying.
Benefits
- Calculates board feet from thickness, width and length
- Totals the cost at your price per board foot
- Matches how hardwood is usually priced
- Free to use in the browser, no account
Practical use cases
- Measuring board feet in a stack of lumber
- Estimating timber cost for a furniture project
- Checking a lumber yard's total before paying
- Comparing prices quoted per board foot
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Frequently asked questions
What is a board foot?
A board foot is a piece of wood 12 inches wide, 12 inches long and 1 inch thick — 144 cubic inches of lumber.
How much extra lumber should I buy?
Buy comfortably more than the bare calculation, because milling, defects, offcuts and grain selection all reduce usable timber. Many woodworkers add a margin on top of their project total, and more for figured or character-grade boards where you reject sections. Running short mid-project often means a second trip and a colour mismatch.
Does nominal thickness differ from actual thickness?
It can. Rough hardwood is often sold at a nominal thickness that shrinks once planed smooth, so a nominal one-inch board finishes thinner. The board-foot price is based on the nominal size, which is what you enter here, but plan your project around the finished dimensions you will actually get.