Quick answer
To find board feet, multiply the thickness in inches by the width in inches by the length in feet, then divide by 12. That gives one board, so multiply by the number of boards for the order. A 1 in by 6 in by 8 ft board is 1 x 6 x 8 / 12 = 4 board feet, so ten of them is 40 board feet.
How to use the board foot calculator
- Enter the thickness and width of the board, and its length.
- Enter how many boards of that size you have.
- Add a price per board foot if you want the total cost.
- Read the board feet per board, the total board feet, the volume in cubic metres, and the cost.
- Enter sizes in inches and feet, or in centimetres and metres.
Worked example
You have ten boards, each 1 in thick, 6 in wide and 8 ft long.
- 1.One board: 1 x 6 x 8 / 12 = 4 board feet
- 2.Ten boards: 4 x 10 = 40 board feet
- 3.Volume: 40 x 0.00236 = about 0.094 cubic metres
- 4.At a price of 3.00 per board foot: 40 x 3.00 = 120.00
When to use this
The formula
One board foot is a piece one foot square and one inch thick, which is 144 cubic inches of wood. It is worked out like this:
board feet = thickness (in) x width (in) x length (ft) / 12, then x number of boards.
Metric sizes are converted to inches and feet first. The result is also shown in cubic metres, where one board foot is about 0.00236 cubic metres.
Board feet per foot of length
Multiply by the length in feet to get the board feet for that size.
| Nominal size | Board feet per foot |
|---|---|
| 1 in x 4 in | 0.33 |
| 1 in x 6 in | 0.50 |
| 1 in x 8 in | 0.67 |
| 1 in x 12 in | 1.00 |
| 2 in x 4 in | 0.67 |
| 2 in x 6 in | 1.00 |
| 2 in x 8 in | 1.33 |
| 2 in x 10 in | 1.67 |
| 2 in x 12 in | 2.00 |
| 4 in x 4 in | 1.33 |
Swipe sideways to see all columns
Buying by the board foot
Hardwood is usually sold by the board foot, often in random widths and lengths, so you measure each board and add them up. Softwood and dressed timber are often sold by the piece or the linear metre instead. If you are quoted a price per board foot, this calculator turns your sizes into the number you are paying for.
Common mistakes
Frequently asked questions
Multiply the thickness in inches by the width in inches by the length in feet, then divide by 12. A 2 in by 8 in by 10 ft board is 2 x 8 x 10 / 12 = 13.33 board feet.
A board foot is a volume of wood: one foot long, one foot wide and one inch thick, which is 144 cubic inches. Timber in North America is priced by the board foot rather than by length.
Use the size you are billed for. Rough timber is close to its nominal size, but dressed timber is smaller, so a nominal 2 in by 4 in is about 1 1/2 in by 3 1/2 in. If you are charged on nominal size, enter nominal.
A log uses a log rule, such as Doyle, Scribner or International, which estimates the usable boards from the small-end diameter and the length. That is different from this calculator, which measures sawn boards.
Enter the price per board foot and the calculator multiplies it by the total board feet. This is the material cost only, before delivery or cutting.
References. The formulas and figures here follow standard construction references. See our Methodology for how we check them. Board foot is the standard lumber measure of 144 cubic inches.
Related calculators
Estimates only. Check supplier specs and local codes before you order or build.