The formula
board feet = linear ft × thickness″ × width″ ÷ 12
Linear (running) feet measure only length — how far the stock stretches. Board feet add the cross-section back in, which is what matters when trim priced by the foot is milled from lumber you're pricing by the board foot.
| Stock | BF per linear ft | Linear ft per BF |
|---|---|---|
| 3/4 × 2-1/2 (casing) | 0.156 | 6.4 |
| 3/4 × 3-1/2 (1×4 actual) | 0.219 | 4.6 |
| 3/4 × 5-1/2 (1×6 actual) | 0.344 | 2.9 |
| 1 × 6 (4/4 rough) | 0.500 | 2.0 |
| 1-1/2 × 3-1/2 (2×4 actual) | 0.438 | 2.3 |
Pricing a whole trim package? Add each profile as a part in the planner.