Board Foot Calculator

Board feet = (thickness in inches × width in inches × length in feet) ÷ 12. The formula uses nominal dimensions — a 2×4 calculates as 2 in × 4 in even though the actual milled size is 1.5 in × 3.5 in. For a 2×4 × 8 ft piece: (2 × 4 × 8) ÷ 12 = 5.33 BF. The calculator above does this for any size and supports metric input (cm and m) with m³ equivalents.

A 2×4 × 8 ft piece is exactly 5.33 board feet: (2 × 4 × 8) ÷ 12 = 64 ÷ 12 = 5.333… BF. At a softwood framing price of $1/BF, that's $5.33 per piece. At $3/BF (Douglas fir, premium grade), $16. The calculator above matches this and lets you set quantity for full bundle pricing — 100 pieces of 2×4 × 8 = 533 BF.

Use nominal — that's what lumber yards quote on. A 2×4 is sold as a 2×4 even though the milled size after planing is 1.5 in × 3.5 in. The board foot price applies to the nominal dimension. The actual size only matters when you're laying out framing or fitting trim. The calculator's preset radio (1×4, 2×6, etc.) uses nominal dimensions; pick Custom only when working with rough-sawn or specialty stock where you actually want to enter the rough thickness.

Hardwood and rough-sawn softwood: per board foot (BF). Dimensional softwood at big-box stores (Home Depot, Lowe's): per piece, with the per-piece price reflecting the BF cost × the BF in that piece. Decking and trim: often per linear foot (LF) — multiply LF × the BF per LF for the species to compare. Convert: a 2×6 has 1 BF per linear foot, so $4/LF = $4/BF for a 2×6. A 1×6 has 0.5 BF per LF, so $2/LF = $4/BF.

Same formula, but hardwood is often sold by the rough size in 4/4 (one inch), 5/4, 6/4, 8/4 thickness rather than nominal 2× sizing. "4/4 oak" means 1-inch rough thickness — calculate as 1 in even though after surfacing it may be 13/16 in. For a 4/4 × 6 in × 10 ft oak board: (1 × 6 × 10) ÷ 12 = 5 BF. The calculator handles this — pick Custom and enter the rough thickness directly (1 in for 4/4, 1.25 in for 5/4, etc.).

Board feet measure VOLUME — used for lumber pricing because thicker boards have more material. Square feet measure AREA — used for sheet goods (plywood, drywall, flooring). Linear feet measure LENGTH along one dimension — used for trim, baseboard, and cordage. A 2×6 × 8 ft piece is 8 BF, 4 sq ft of face area, and 8 LF of length. Don't confuse them at the lumber yard — if a price says "$/LF" you're paying by the foot of length regardless of thickness.

Price per BF = total price ÷ board feet. If a 2×6 × 12 ft piece costs $18: BF = (2 × 6 × 12) ÷ 12 = 12 BF, so $18 ÷ 12 = $1.50/BF. The calculator above does the inverse — enter your $/BF and it gives you total cost. Useful for comparing species: $1.50/BF for pine vs $6/BF for cherry tells you the cherry costs 4× more per equivalent volume even if a single piece looks similarly priced.

Yes — pick Metric in the unit selector at the top. Thickness and width switch to centimeters, length to meters. Presets fill the international metric SKU dimensions: 2×4 fills 5 × 10 cm (50 × 100 mm), 2×6 fills 5 × 15 cm, etc. Board feet stays as the primary output (it's an imperial unit and the lumber industry uses it globally), with the m³ equivalent shown in parentheses. 1 BF = 0.00236 m³. Common conversions: 5 cm × 10 cm × 2.4 m = 5.09 BF (≈ 0.012 m³). Your unit choice persists across pages via localStorage.