Board Foot Calculator
The board feet in a piece or a stack of lumber from its thickness, width and length — the unit hardwood is sold by — with the total for a quantity, the cost at a price per board foot, and the equivalent in cubic metres.
A board foot is a volume: 144 cubic inches, a piece one foot square and an inch thick.
How the board foot calculator works
A board foot is a volume: 144 cubic inches, a piece one foot square and an inch thick. Thickness in inches times width in inches times length in feet, over twelve, gives the board feet in a piece — and hardwood yards price by it, using nominal rough thickness in quarters (4/4 is one inch, 8/4 two). Softwood is usually sold by the piece or the linear foot, but the board-foot figure still says how much wood you are buying.
Formula: board feet = thickness (in) × width (in) × length (ft) / 12; 1 board foot = 0.00236 m³
Worked examples
| Inputs | Board feet per piece | Note |
|---|---|---|
| Ten 1 × 6 boards, 8 ft long | 3.814 | 40 board feet |
| Thick stock | — | twice the board feet |
| A single wide slab | — | 16 board feet |
FAQFrequently asked questions
What is a board foot?
A volume of timber: one foot by one foot by one inch, or 144 cubic inches. It is the unit hardwood lumber is priced by in North America and in many specialist timber yards elsewhere.
Nominal or actual size?
Hardwood is sold on the rough-sawn size before planing — 4/4 stock counts as one inch thick even after it is dressed to 13/16. Use the nominal figure the yard bills on.
How many board feet in a 2 × 4?
A nominal 2 × 4 is two thirds of a board foot per linear foot; an eight-footer is 5.33 board feet. Softwood is rarely priced that way, but the figure compares wood volumes.
How does it relate to cubic metres?
One board foot is 0.00236 cubic metres, so 424 board feet make a cubic metre. Metric yards price by the cubic metre or the linear metre.
Why does the calculation ignore waste?
Because the yard charges for what you buy. Add 10 to 20% to the quantity for defects and cutting when you plan the project.
Where these figures come from
- The Engineering ToolBox — material densities, coverage and unit data — bulk densities, concrete at 2,400 kg/m³, board and sheet sizes
- Brick Development Association — brick sizes and quantities — 215 × 102.5 × 65 mm, 60 bricks per m²
- UK Government — Approved Documents (Building Regulations) — Building Regulations guidance
Last checked: September 2026. Coverage rates and material sizes are typical manufacturer figures — check the product you buy.