Lumber Calculator
Calculate lumber requirements including board feet, linear feet, and number of pieces needed for your construction and woodworking projects.
Lumber Calculator
Results
Enter your values and click "Calculate" to see results
Frequently Asked Questions
Common questions about lumber measurements and calculations
What is a board foot?
A board foot is a unit of volume for measuring lumber in the United States and Canada. One board foot equals the volume of a one-foot length of a board one foot wide and one inch thick (1 × 12 × 12 inches). It is equivalent to 144 cubic inches or approximately 0.00236 cubic meters.
How do you calculate board feet?
To calculate board feet, multiply the thickness (in inches) × width (in inches) × length (in feet) ÷ 12. For example, a 2×4 that is 8 feet long would be (2 × 4 × 8) ÷ 12 = 5.33 board feet.
Why are my 2×4s actually 1.5×3.5 inches?
Lumber dimensions refer to the rough cut size before the wood is dried and planed smooth. During processing, about 1/4 to 1/2 inch is removed from each dimension. For example, a 2×4 starts as a rough 2×4 but finishes at the lumberyard as approximately 1.5×3.5 inches.
What's the difference between linear feet and board feet?
Linear feet is simply a measurement of length in feet, regardless of width or thickness. Board feet is a volume measurement that takes into account the thickness, width, and length of lumber. For lumber pricing and ordering, board feet is typically used.
How much extra lumber should I order for waste?
As a general rule, you should add 10-15% extra for waste, cutting errors, and damaged pieces. For complex projects with many cuts or joints, consider adding up to 20%. For very simple projects with few cuts, 5-10% may be sufficient.
Lumber Calculator Tips
Expert advice for accurately calculating your lumber needs
Consider Nominal vs. Actual Dimensions
Remember that lumber dimensions are nominal, not actual. For example, a 2×4 actually measures about 1.5×3.5 inches. Our calculator accounts for this difference.
Add Waste Factor
Always include a waste factor of 10-15% for most projects to account for cuts, mistakes, and damaged pieces. For complex projects with many angles, consider 15-20%.
Choose the Right Wood Type
Select appropriate wood types for your project. Pressure-treated for outdoor exposure, hardwoods for furniture, and softwoods for general construction.
Standard Lumber Lengths
Most lumber is sold in 8, 10, 12, 14, 16, and sometimes 20-foot lengths. Plan your cuts to minimize waste by considering these standard lengths.
Check Building Codes
Always verify local building codes for requirements on lumber dimensions and spacing, especially for structural projects like decks, walls, and floors.
Use Proper Span Tables
For joists, beams, and rafters, consult span tables to ensure your lumber is strong enough for the span and load it needs to support.
Understanding Lumber Types
Choosing the right type of lumber for your project is crucial for both structural integrity and aesthetic appeal. Different wood species offer unique characteristics in terms of strength, durability, appearance, and cost.
Softwoods
Derived from coniferous trees, softwoods are the most common and economical choice for construction projects.
- Pine: Light, easy to work with, takes stain well
- Cedar: Naturally resistant to rot and insects
- Spruce: Strong with straight grain, ideal for framing
- Douglas Fir: High strength-to-weight ratio
Hardwoods
From deciduous trees, hardwoods are typically denser, more durable, and often used for fine woodworking and furniture.
- Oak: Durable with prominent grain, excellent for furniture
- Maple: Hard, resistant to wear, with subtle grain
- Cherry: Reddish-brown, darkens with age, fine grain
- Walnut: Rich dark color, premium choice for cabinets
Engineered Wood Products
Manufactured by binding wood fibers, strands, or veneers with adhesives to create composite materials with enhanced properties.
Lumber Grade Comparison
Understanding lumber grades helps you select the right material for your specific project needs
| Grade | Appearance | Recommended Uses | Relative Cost |
|---|---|---|---|
| Select/Clear | Minimal knots, uniform appearance, highest quality | Furniture, cabinetry, trim, high-visibility areas |
$$$
|
| No. 1 | Few small knots, good appearance | High-quality construction, shelving, painted trim |
$$
|
| No. 2 | More knots, some minor defects, standard grade | General construction, framing, utility projects |
$$
|
| No. 3 | Larger knots, more defects, still structurally sound | Utility projects, temporary structures, blocking |
$
|
Note: Lumber grades may vary slightly between different grading organizations and wood species. Always check with your supplier for specific grade characteristics.
Eco-Friendly Lumber Choices
Making sustainable choices in your lumber selection helps reduce environmental impact and promote responsible forestry practices.
FSC Certified Wood
Forest Stewardship Council certification ensures the lumber comes from responsibly managed forests that provide environmental, social, and economic benefits.
Reclaimed Wood
Salvaged from old buildings, barns, and other structures, reclaimed wood reduces the demand for new lumber while adding character and history to your project.
Rapidly Renewable Woods
Species like bamboo and eucalyptus grow quickly and can be harvested in 5-10 years compared to 50+ years for traditional hardwoods.
Environmental Impact Reduction
By choosing sustainable lumber options, you can significantly reduce the environmental footprint of your construction project:
Certification Labels to Look For:
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