Board Foot Calculator

Lumber Volume & Cost Calculator

Calculate board feet, volume, and cost for lumber projects. Essential for carpenters, builders, and woodworkers to estimate wood requirements and costs.

Examples

Click on any example to load it into the calculator.

Common 2x4 Lumber

Common

Standard 2x4 lumber piece (8 feet long, 3.5 inches wide, 1.5 inches thick).

Length: 8 ft

Width: 3.5 in

Thickness: 1.5 in

Quantity: 1 pieces

Price per Board Foot: $3.50

Decking Boards

Decking

Pressure-treated decking boards for outdoor projects.

Length: 12 ft

Width: 5.5 in

Thickness: 1 in

Quantity: 20 pieces

Price per Board Foot: $4.25

Plywood Sheet

Plywood

Standard 4x8 plywood sheet (4 feet by 8 feet, 0.75 inches thick).

Length: 8 ft

Width: 48 in

Thickness: 0.75 in

Quantity: 1 pieces

Price per Board Foot: $2.80

Volume Only Calculation

Volume Only

Calculate board feet without pricing information.

Length: 10 ft

Width: 8 in

Thickness: 2 in

Quantity: 5 pieces

Other Titles
Understanding Board Foot Calculator: A Comprehensive Guide
Learn how to calculate board feet, understand lumber measurements, and estimate costs for your woodworking and construction projects.

What is a Board Foot?

  • The Standard Unit of Lumber Measurement
  • Why Board Feet Matter
  • Understanding the Formula
A board foot is the standard unit of measurement for lumber in the United States and Canada. It represents a volume of wood that is 1 foot long, 1 foot wide, and 1 inch thick, equivalent to 144 cubic inches or 1/12 of a cubic foot.
The Board Foot Formula
The basic formula for calculating board feet is: Board Feet = (Length × Width × Thickness) ÷ 144. Where length is in feet, and both width and thickness are in inches. This formula accounts for the fact that 1 board foot equals 144 cubic inches.
Why Use Board Feet?
Board feet provide a standardized way to measure and price lumber regardless of the specific dimensions. This allows for fair pricing and easy comparison between different sizes and types of wood.

Key Concepts:

  • 1 board foot = 1 ft × 1 ft × 1 in = 144 cubic inches
  • Board feet are used for pricing and inventory
  • The formula standardizes different lumber sizes

Step-by-Step Guide to Using the Board Foot Calculator

  • Measuring Your Lumber
  • Entering the Correct Values
  • Understanding Your Results
This calculator helps you determine the board feet, volume, and cost of lumber for your projects. Follow these steps to get accurate measurements and cost estimates.
1. Measure Your Lumber Dimensions
Start by measuring the length, width, and thickness of your lumber. Length should be measured in feet, while width and thickness should be measured in inches. For example, a 2x4 that is 8 feet long would have length = 8, width = 3.5, and thickness = 1.5 inches.
2. Enter the Quantity
Specify how many pieces of lumber you need with the same dimensions. This allows you to calculate the total board feet and cost for your entire project.
3. Add Pricing Information (Optional)
If you know the price per board foot for your lumber type, enter it to calculate the total cost. Different wood species and grades have different prices per board foot.
4. Review Your Results
The calculator will show you the board feet per piece, total board feet, total volume in cubic feet, and if pricing was provided, the total cost and cost per piece.

Common Measurements:

  • 2x4: 3.5" × 1.5" (actual dimensions)
  • 2x6: 5.5" × 1.5" (actual dimensions)
  • 1x6: 5.5" × 0.75" (actual dimensions)

Real-World Applications of Board Foot Calculations

  • Construction Projects
  • Woodworking and Carpentry
  • Cost Estimation and Budgeting
Board foot calculations are essential in various construction and woodworking applications, from small DIY projects to large commercial construction.
Construction and Framing
In residential and commercial construction, board feet are used to estimate the amount of lumber needed for framing, decking, and structural components. Accurate calculations help prevent over-ordering or running short on materials.
Furniture Making and Woodworking
Woodworkers use board feet to plan projects, estimate material costs, and ensure they purchase the right amount of lumber. This is especially important when working with expensive hardwoods.
Inventory Management
Lumber yards and wood suppliers use board feet to track inventory, set prices, and manage stock levels. This standardized measurement system allows for efficient business operations.

Project Examples:

  • Deck construction: Calculate joists, decking, and railings
  • Furniture building: Estimate hardwood requirements
  • Home renovation: Plan framing and trim materials

Common Misconceptions and Correct Methods

  • Nominal vs. Actual Dimensions
  • Pricing Variations
  • Measurement Accuracy
Understanding the difference between nominal and actual dimensions, as well as other common misconceptions, is crucial for accurate board foot calculations.
Nominal vs. Actual Dimensions
Lumber is sold by nominal dimensions (e.g., 2x4), but the actual dimensions are smaller due to drying and planing. A 2x4 actually measures 1.5" × 3.5". Always use actual dimensions for board foot calculations.
Pricing Variations by Species and Grade
Different wood species and grades have significantly different prices per board foot. Pine might cost $3-5 per board foot, while exotic hardwoods can cost $20-50 per board foot or more.
Waste and Overage Considerations
It's wise to add 10-15% to your board foot calculations to account for waste, defects, and cutting errors. This ensures you have enough material to complete your project.

Important Notes:

  • Always measure actual dimensions, not nominal
  • Account for waste in your calculations
  • Consider wood species and grade for pricing

Mathematical Derivation and Examples

  • Understanding the Formula
  • Step-by-Step Calculations
  • Advanced Applications
The board foot formula is derived from the definition of a board foot and basic volume calculations. Understanding the mathematics helps ensure accurate measurements.
Formula Derivation
Since 1 board foot = 1 ft × 1 ft × 1 in = 12 in × 12 in × 1 in = 144 cubic inches, we divide the total volume in cubic inches by 144 to get board feet. The formula: Board Feet = (L × W × T) ÷ 144, where L is in feet and W, T are in inches.
Example Calculation
For a piece 8 feet long, 6 inches wide, and 2 inches thick: Board Feet = (8 × 6 × 2) ÷ 144 = 96 ÷ 144 = 0.67 board feet. For 10 pieces: Total Board Feet = 0.67 × 10 = 6.67 board feet.
Volume Conversion
To convert board feet to cubic feet: Cubic Feet = Board Feet ÷ 12 (since 1 cubic foot = 12 board feet). For cost calculation: Total Cost = Board Feet × Price per Board Foot.

Calculation Examples:

  • 8' × 6" × 2" = 0.67 board feet
  • 10 pieces = 6.67 total board feet
  • At $4/board foot = $26.68 total cost