Board Feet Calculator
Calculate board feet for lumber and hardwood. Convert between board feet, linear feet, and square feet with cost estimates.
Use nominal thickness (e.g., 2 for a 2×4)
How to Use This Calculator
Board feet is the standard measurement for hardwood lumber pricing. Here's how to calculate your lumber needs:
- Enter the thickness and width in inches. Use the quick-select buttons for common lumber sizes.
- Enter the length of each board in feet.
- Enter the quantity of boards you need.
- Optionally enter the price per board foot to calculate total cost.
- Click 'Calculate' to see board feet, linear feet, and square feet.
Why This Matters
Understanding board feet is essential when buying hardwood lumber, as most lumber yards price by the board foot. Unlike dimensional softwood (sold by the piece), hardwood prices vary by species, grade, and the total board footage you're purchasing.
- Calculate exact lumber costs before visiting the lumber yard
- Compare prices between different suppliers accurately
- Convert between board feet, linear feet, and square feet
- Estimate material costs for woodworking projects
- Avoid over-buying expensive hardwoods
Worked Examples
Hardwood Table Top
You need 5 pieces of 8/4 (2-inch thick) walnut, 6 inches wide, 6 feet long.
Calculation: (2 × 6 × 6) ÷ 12 = 6 board feet per piece × 5 pieces = 30 board feet
Result: At $12/board foot for walnut, total cost is $360.
Cabinet Sides
You need 8 pieces of 4/4 (1-inch thick) maple, 12 inches wide, 4 feet long.
Calculation: (1 × 12 × 4) ÷ 12 = 4 board feet per piece × 8 pieces = 32 board feet
Result: At $6/board foot for maple, total cost is $192.
2×6 Lumber Comparison
A lumberyard sells 2×6×12 boards at $9.50 each. What's the per-board-foot cost?
Calculation: (2 × 6 × 12) ÷ 12 = 12 board feet per board
Result: $9.50 ÷ 12 board feet = $0.79 per board foot.
Common Mistakes to Avoid
- Confusing nominal vs actual dimensions - remember that a 2×4 is actually 1.5×3.5 inches. Board feet use nominal dimensions.
- Mixing up the formula - thickness and width are in inches, but length is in feet.
- Forgetting waste factor - add 15-20% for cuts, defects, and mistakes when ordering hardwood.
- Not accounting for rough vs surfaced - rough lumber may need 1/8" to 1/4" removed per face during surfacing.
- Assuming board feet equals square feet - they're only equal for 1-inch thick material.