Lumber Calculator
Estimate the lumber you need for your construction or DIY project, calculate costs, and plan your materials.
Pro Tip: Always buy 10-15% more lumber than calculated to account for waste, mistakes, and variations in wood quality.
Calculation Method
Best for raw lumber and timber purchases.
Best for finished lumber like molding, trim, or decking.
Board Feet Calculator
Linear Feet Calculator
Typical waste is 10-15% for most projects.
Common Lumber Sizes
Lumber Calculation Results
Board Feet per Piece:
Total Board Feet:
Estimated Cost:
Recommended Purchase (with 10% waste): board feet
Required Linear Feet:
With Waste Added:
Estimated Cost:
About Our Lumber Calculator
Our Lumber Calculator is a powerful tool designed to help contractors, DIY enthusiasts, and homeowners accurately estimate the amount of lumber needed for construction and woodworking projects. Whether you're building a deck, framing a house, or crafting furniture, precise lumber calculations can save you time, money, and reduce waste.
What is a Board Foot?
A board foot is a unit of volume for lumber in the United States and Canada. One board foot equals 1 foot × 1 foot × 1 inch (12 in × 12 in × 1 in) or 144 cubic inches. It's the standard measurement used when purchasing hardwoods and larger dimension lumber.
How to Calculate Board Feet
The formula for calculating board feet is:
Board Feet = (Thickness in inches × Width in inches × Length in feet) ÷ 12
Linear Feet vs. Board Feet
While board feet measure volume, linear feet measure the total length of lumber regardless of width or thickness. Linear feet are often used for pricing and purchasing trim, molding, and other finished lumber products where the cross-sectional dimensions are consistent.
Key Features:
- Calculate board feet for raw lumber purchases
- Calculate linear feet for finished lumber like molding and trim
- Estimate costs based on current lumber prices
- Account for waste with automatic percentage adjustments
- Quick selection of standard lumber dimensions
- Instant results for project planning
How to Use:
- Select calculation method (Board Feet or Linear Feet)
- For board feet: enter lumber dimensions, quantity, and price
- For linear feet: enter total length needed, waste percentage, and price
- Click "Calculate Lumber" to see your results
- Review the estimated amount and cost
Applications:
Construction Projects: Frame houses, build decks, construct sheds
Woodworking: Plan material needs for furniture, cabinets, and crafts
Home Renovation: Estimate flooring, trim, and molding requirements
Material Budgeting: Calculate costs accurately for project proposals
Inventory Management: Track lumber usage and stock for businesses
Nominal vs. Actual Lumber Sizes
It's important to understand that lumber dimensions often refer to nominal sizes, not actual dimensions. For example, a "2×4" piece of lumber actually measures approximately 1.5 inches × 3.5 inches after processing. Our calculator uses nominal dimensions for easier reference, but keep this difference in mind when planning precise fits.
Common Nominal vs. Actual Sizes:
Whether you're a professional contractor or a weekend DIY enthusiast, our Lumber Calculator provides the accuracy and flexibility you need to plan your projects efficiently and minimize waste.
Frequently Asked Questions
How much extra lumber should I buy for waste?
For most construction and woodworking projects, it's recommended to purchase 10-15% more lumber than your calculations indicate. This accounts for waste from cutting, damaged pieces, mistakes, and variations in wood quality. For complex projects with many angle cuts, consider increasing to 15-20%. For simple projects with mostly straight cuts, 10% may be sufficient. Always factor in the complexity of your project and your experience level when determining the waste percentage.
Why are actual lumber dimensions different from nominal dimensions?
Lumber dimensions are labeled with their nominal (named) size rather than their actual dimensions. This difference exists because the nominal size refers to the rough-cut green lumber dimensions before it's dried and planed smooth at the mill. During processing, the lumber shrinks and is planed down, resulting in the actual dimensions being smaller than the nominal size. This practice dates back to when lumber was sold rough-sawn; the naming convention remained even as processing methods changed. For accurate project planning, always use the actual dimensions in your measurements.
What's the difference between hardwood and softwood lumber calculations?
When calculating lumber quantities, hardwoods are typically sold by board feet, while softwoods are often sold by the piece or linear foot. Hardwoods (like oak, maple, or walnut) are usually purchased for furniture, cabinetry, and fine woodworking, where the volume of wood matters more than the length. Softwoods (like pine, cedar, or fir) are commonly used in construction and come in standard dimensions and lengths. Additionally, hardwoods are usually rough-sawn and may require further processing, while construction-grade softwood lumber is typically sold already dimensioned and surfaced.