How this calculator works
A board foot is 144 cubic inches — a piece 1 in thick, 12 in wide and 12 in long. With length in feet, board feet = thickness (in) × width (in) × length (ft) ÷ 12.
Board feet = Thickness (in) × Width (in) × Length (ft) ÷ 12 × Quantity
Worked example
Using the default values in the calculator above:
| Input | Value |
|---|---|
| Thickness | 1 in |
| Width | 6 in |
| Length | 8 ft |
| Number of boards | 10 |
| Price per board foot (optional) | $0 |
| Result | Value |
|---|---|
| Total board feet | 40 BF |
| Board feet per board | 4 BF |
Step by step:
- One board = 1 × 6 × 8 ÷ 12 = 4 BF
- × 10 boards = 40 BF
Board feet of common lumber sizes
One board, nominal dimensions.
| Board | Board feet per board |
|---|---|
| 1×6 × 8 ft | 4 BF |
| 2×4 × 8 ft | 5.33 BF |
| 2×6 × 10 ft | 10 BF |
| 2×10 × 12 ft | 20 BF |
| 4×4 × 8 ft | 10.67 BF |
| 8/4 × 8 in × 10 ft hardwood | 13.33 BF |
Common mistakes to avoid
- Using actual planed sizes when the yard prices on nominal sizes (or the other way round) — ask how they measure.
Frequently asked questions
How many board feet in a 2×4×8?
Using nominal size: 2 × 4 × 8 ÷ 12 ≈ 5.33 board feet.
What does 4/4 mean?
“Four-quarter” lumber is nominally 1 inch thick; 8/4 is 2 inches.