Enter dimensions — results update instantly. Uses BF = (T in × W in × L ft) ÷ 12.
A board foot (BF) is a volume measure for lumber equal to 144 in³ (12 in × 12 in × 1 in). The calculator uses the standard formula:
Values update as you type. Use the presets for common dressed sizes (e.g., 2×4 actual 1.5 in × 3.5 in).
One board foot is a volume of wood equal to 144 cubic inches. You can also think of it as 1 ft² of surface at 1 inch thick, or 1/12 of a cubic foot.
Because most lumber is sold in “1×, 2×” sizes but planed to slightly smaller actual dimensions, many calculations use actual thickness and width.
A nominal 2×4 actually measures about 1.5 in × 3.5 in after drying and planing. For BF estimates, using actual sizes gives more realistic totals. This tool’s presets fill in typical dressed sizes.
Useful when estimating long runs (BF/ft = T × W ÷ 12).
| Size (actual) | BF per foot |
|---|---|
| 1×4 (0.75″ × 3.5″) | 0.219 |
| 1×6 (0.75″ × 5.5″) | 0.344 |
| 1×8 (0.75″ × 7.25″) | 0.453 |
| 2×4 (1.5″ × 3.5″) | 0.438 |
| 2×6 (1.5″ × 5.5″) | 0.688 |
| 2×8 (1.5″ × 7.25″) | 0.906 |
| 2×10 (1.5″ × 9.25″) | 1.156 |
| 2×12 (1.5″ × 11.25″) | 1.406 |
