Linear Foot to Board Foot Calculator

Why This One Is Different

Got a lumber quote in linear feet but need a board-foot total for a takeoff or a different supplier's bid? This calculator converts one to the other in one step. Linear feet and board feet measure different things: one is length, the other is volume, and the conversion between them depends only on your board's cross-section, not on how long the boards are (the formula is nominal thickness times nominal width, divided by 12). That ratio produces one clean, checkable number: a 2x6 converts at exactly 1.000 board foot per linear foot, whether you're buying 8 feet or 800. A 2x4 converts at 0.667 bf/lf, a 2x10 at 1.667 bf/lf. Enter your length and the calculator applies that ratio automatically, so you can move between a supplier's linear-foot quote and a board-foot takeoff without doing the arithmetic by hand.

Where the Numbers Come From

• The ratio depends only on your board's cross-section, never its length: bf per linear foot = (nominal thickness in × nominal width in) ÷ 12. Source: lumber.ts bfPerLinearFoot(), closed-form definition
• A nominal 2×6 converts at exactly 1.000 board foot per linear foot (2×6÷12), the cleanest checkable ratio in the board-foot system. Source: worked example, closed-form arithmetic
• A nominal 2×4 converts at 0.667 bf/lf and a nominal 2×10 at 1.667 bf/lf: wider or thicker cross-sections carry proportionally more board feet per running foot, per the same nominal-dimension convention as board-foot pricing. Source: lumber.ts bfPerLinearFoot() convention; SPIB PS 20-20 nominal-dimension basis (construction-estimating canon)