Board Feet Calculator

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Board feet is the standard unit of measurement for lumber — especially hardwoods, specialty woods, and rough-sawn boards. Whether you're building furniture, installing hardwood floors, or framing a structure, knowing exactly how many board feet you need helps you budget accurately and avoid material shortages mid-project.

Our Board Feet Calculator accepts any custom dimensions — thickness in inches, width in inches, length in feet, and quantity of identical boards. The formula multiplies all three dimensions, divides by 144 (the volume of one board foot in cubic inches), then multiplies by quantity. It works for everything from 1/4″ veneer to 12×12 timbers.

Important note: always use actual dimensions, not nominal sizes. A "2×4" is actually 1.5″ thick × 3.5″ wide. The difference between nominal and actual comes from the milling process — rough lumber is planed down to its finished (actual) size. If you're buying rough-sawn lumber, use the rough dimensions directly.

When estimating total project needs, add 10-15% extra for hardwoods (due to waste from cutting around defects) and 5-10% for dimensional framing lumber. Buy lumber from the same mill when possible to ensure consistent grain patterns and moisture content.

Công thức
Board Feet = (Thickness × Width × Length) ÷ 12 × Quantity

Câu hỏi thường gặp

What is a board foot?
A board foot is a volume measurement equal to 1 inch thick × 12 inches wide × 1 foot long. It's the standard unit for buying and selling lumber — especially hardwoods and specialty woods.
How do nominal sizes convert to actual sizes?
A 2×4 is actually 1.5″ × 3.5″, a 2×6 is 1.5″ × 5.5″, and a 1×4 is 0.75″ × 3.5″. Use actual dimensions when calculating board feet, not nominal sizes.
Why is lumber sold by board foot?
Board feet represents the actual volume of wood in a board, making pricing consistent regardless of board dimensions. Hardwoods are almost exclusively sold by board foot since they're often purchased in random widths and lengths.
How do I convert board feet to square feet?
For flooring and paneling: Square Feet = Board Feet × 12 ÷ (Thickness in Inches). For example, 1″ thick flooring: 12 board feet = 12 sq ft of surface area.