Home › Board Foot Calculator
Board Foot Calculator
A board foot is the unit hardwood lumber is priced in. Enter the thickness, width and length of your boards and the number of pieces, and get the total board feet and the cost at your price per board foot.
Results are estimates. Soil, stone and mulch settle, weigh differently and vary by supplier. Confirm quantities and local requirements before ordering.
How to calculate it
One board foot is 144 cubic inches, the volume of a board 1 inch thick, 12 inches wide and 12 inches long.
Formula: board feet = thickness (in) × width (in) × length (ft) ÷ 12. With the length in inches, divide by 144 instead.
Multiply by the number of pieces for the total. Lumber yards often price boards by the board foot using the nominal size (a "1×6" counts as 1 in × 6 in even though it is thinner), so ask which dimensions the price is based on.
Worked example
Ten boards, each 1 in thick, 6 in wide and 8 ft long:
| Board feet, per piece | 4 bd ft |
|---|---|
| Board feet, total | 40 bd ft 10 pieces |
| Cubic feet | 3.333 ft³ |
| Cubic inches | 5,760 in³ |
| Cubic meters | 0.0944 m³ |
Common boards, board feet each (nominal size)
| Board | Length | Board feet |
|---|---|---|
| 1×6 | 8 ft | 4 |
| 1×12 | 8 ft | 8 |
| 2×4 | 8 ft | 5.33 |
| 2×6 | 8 ft | 8 |
| 2×4 | 10 ft | 6.67 |
| 4/4 (1 in) × 8 in | 10 ft | 6.67 |
Tips
- Hardwood is sold in quarters of an inch: 4/4 is 1 in, 5/4 is 1¼ in, 6/4 is 1½ in and 8/4 is 2 in.
- Buy 15–20% more than the finished need to allow for defects, trimming and milling losses.
- Softwood framing lumber is usually priced per piece or per linear foot, not per board foot.
- Dimensions are rough size. After planing, boards are thinner, but the price is normally on rough size.
Frequently asked questions
How many board feet are in a 2×4×8?
Using the nominal size, 2 × 4 × 8 ÷ 12 = 5.33 board feet.
How do you calculate board feet?
Multiply thickness in inches by width in inches by length in feet, then divide by 12.
How many board feet are in a 1×6×8?
1 × 6 × 8 ÷ 12 = 4 board feet.
Is a board foot the same as a square foot?
No. A square foot measures area, while a board foot measures volume. They match only for a board exactly 1 inch thick.