Roofing & buildingFree calculator
Hardwood and many timber yards price lumber by the board foot or cubic metre. Enter the size and number of boards to get the total volume and cost.
Your shopping list
How to measure
- Measure the thickness and width in inches (or centimetres) and the length in feet (or metres).
- Use nominal thickness for rough lumber (for example 4/4 = 1 in).
- Enter how many boards you need and the price per board foot or m³.
The formula
Board feet = thickness (in) × width (in) × length (ft) ÷ 12 Cubic metres = thickness (m) × width (m) × length (m) 1 m³ ≈ 424 board feet
Worked example
Ten 1 × 6 in hardwood boards (4/4), 8 ft long, are 4 board feet each, 40 board feet in total. At about $6 per board foot for red oak that is $240.
Tips before you buy
- Buy 10–15% extra to allow for defects, knots and cutting.
- Rough lumber shrinks when planed; buy for the finished size you need.
- Softwood from big-box stores is usually priced per piece, not per board foot.
Frequently asked questions
What is a board foot?
A volume of wood 12 in × 12 in × 1 in thick, or 144 cubic inches.
How many board feet in a cubic metre?
About 424 board feet.
Do I use nominal or actual size?
Hardwood dealers use nominal thickness (like 4/4 or 8/4) and actual width and length.
Results are estimates for planning only. Always check quantities with your supplier before you buy.