Board Foot Calculator

Calculate lumber volume in board feet for woodworking and construction projects.

Thickness (in):

Width (in):

Length (ft):

Quantity:

What is a Board Foot?

A board foot is a unit of volume for lumber equal to:

1 board foot = 1″ (thickness) × 12″ (width) × 12″ (length)

Board Foot Formula

Board Feet = (Thickness (in) × Width (in) × Length (ft)) ÷ 12

Common Lumber Dimensions

Nominal Size	Actual Size	Board Feet per 8′
1×4	0.75″ × 3.5″	2.33
2×4	1.5″ × 3.5″	4.67
1×6	0.75″ × 5.5″	3.5
2×6	1.5″ × 5.5″	7.0

What is a Board Foot and How is it Calculated?

A board foot (bd ft) is the standard unit of measurement for lumber in North America. It represents the volume of a one-foot length of a board that is one foot wide and one inch thick. Understanding board feet is essential for accurately pricing and purchasing lumber.

The formula for calculating board feet is straightforward:

Board Foot Formula:

Board Feet = (Length in feet × Width in inches × Thickness in inches) ÷ 12

For multiple pieces: Multiply the result by the quantity

For example, a board that is 8 feet long, 6 inches wide, and 2 inches thick would be calculated as:

(8 × 6 × 2) ÷ 12 = 8 board feet

Why Board Foot Measurement Matters:

Standardized pricing for lumber of different dimensions
Accurate comparison between different wood species and sizes
Proper project planning and material estimation
Industry standard for lumber yards and woodworkers

Common Lumber Dimensions in Board Feet

Understanding how standard lumber sizes translate to board feet helps with quick estimation and planning. Here are some common examples:

Lumber Size	Length	Board Feet	Common Use
2×4	8 feet	5.33 bd ft	Framing, structure
2×6	8 feet	8 bd ft	Decking, joists
2×8	8 feet	10.67 bd ft	Beams, headers
2×10	8 feet	13.33 bd ft	Floor joists, beams
1×4	8 feet	2.67 bd ft	Trim, crafts
1×6	8 feet	4 bd ft	Siding, paneling
4×4	8 feet	10.67 bd ft	Posts, supports

Important Note: Nominal lumber sizes (like 2×4) refer to the rough-cut dimensions. Actual dimensions are smaller after planing and drying. A 2×4 actually measures approximately 1.5″ × 3.5″. Always use actual dimensions for precise board foot calculations.

How to Calculate Board Feet for Different Wood Types

Different wood species have varying densities and characteristics that affect their board foot calculations and pricing. Here’s what you need to know:

Hardwood vs. Softwood Board Foot Calculations:

Pricing Variations: Hardwoods generally cost more per board foot due to density, durability, and appearance.

Softwoods: Typically sold by linear foot or board foot. Common examples include pine, cedar, fir, and spruce.

Hardwoods: Almost always sold by board foot. Examples include oak, maple, walnut, and cherry.

Average Price Ranges per Board Foot (2023):

Wood Type	Price Range per Bd Ft	Common Uses
Pine (Common)	$2 – $4	Framing, construction
Cedar	$4 – $8	Decking, outdoor furniture
Oak (Red)	$6 – $12	Furniture, flooring
Maple	$8 – $15	Cabinetry, flooring
Walnut	$12 – $20	Fine furniture, trim
Cherry	$8 – $14	Furniture, cabinetry

Hardwood vs. Softwood Board Foot Calculations:

Softwoods: Typically sold by linear foot or board foot. Common examples include pine, cedar, fir, and spruce.
Hardwoods: Almost always sold by board foot. Examples include oak, maple, walnut, and cherry.
Pricing Variations: Hardwoods generally cost more per board foot due to density, durability, and appearance.

Average Price Ranges per Board Foot (2023):

Wood Type	Price Range per Bd Ft	Common Uses
Pine (Common)	$2 – $4	Framing, construction
Cedar	$4 – $8	Decking, outdoor furniture
Oak (Red)	$6 – $12	Furniture, flooring
Maple	$8 – $15	Cabinetry, flooring
Walnut	$12 – $20	Fine furniture, trim
Cherry	$8 – $14	Furniture, cabinetry

Project Planning Examples:

Deck Construction: Calculate total board feet needed for deck boards, railings, and structural members
Furniture Building: Estimate material costs for tables, chairs, and cabinets
Home Renovation: Plan for trim, flooring, and custom millwork
Woodworking Projects: Budget for small crafts and artistic pieces

Let’s calculate the board footage needed for a simple bookshelf:

2 sides: 6′ × 10″ × 1″ = 10 bd ft
5 shelves: 3′ × 10″ × 1″ = 12.5 bd ft
1 top: 3′ × 10″ × 1″ = 2.5 bd ft
1 back: 6′ × 3′ × 0.25″ = 4.5 bd ft

Total: 29.5 board feet (plus 10% waste factor = 32.45 bd ft)

Professional Tip: Always add a waste factor of 10-15% to your calculations to account for cutting errors, defects in the wood, and unexpected project changes.

Frequently Asked Questions About Board Feet

How many board feet are in a 2x4x8?

A 2×4 that is 8 feet long contains approximately 5.33 board feet. This is calculated as: (8 feet × 4 inches × 2 inches) ÷ 12 = 64 ÷ 12 = 5.33 board feet.

What’s the difference between board feet and square feet?

Square feet measures area (length × width), while board feet measures volume (length × width × thickness). Board feet accounts for the thickness of the lumber, making it the standard measurement for pricing dimensional lumber.

How do you convert square feet to board feet?

To convert square feet to board feet, multiply the square footage by the thickness in inches. For example, 10 square feet of 1-inch thick lumber equals 10 board feet. For 2-inch thick lumber, it would be 20 board feet.

Why is board foot measurement used instead of linear foot?

Board foot measurement accounts for both the width and thickness of lumber, providing a consistent way to price wood regardless of dimensions. Linear foot pricing would be unfair for wider or thicker boards that contain more wood volume.

How much does lumber typically cost per board foot?

Lumber prices vary widely by species, quality, and market conditions. Common construction softwoods like pine typically cost $2-4 per board foot, while hardwoods like oak or maple range from $6-15 per board foot. Exotic woods can cost $20+ per board foot.

What does MBF mean in lumber measurement?

MBF stands for “Thousand Board Feet.” It’s commonly used in the lumber industry for large quantities. 1 MBF = 1,000 board feet. This unit is typically used for wholesale lumber purchases and large construction projects.

About Our Construction Tools

SUC

Construction & Engineering Tools Team at Smart Unit Calculator

Our team of construction specialists and engineers develops and maintains these practical calculation tools for contractors, builders, architects, DIY enthusiasts, and construction professionals.

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All construction calculations use industry-standard formulas and building codes to ensure accurate, reliable results for real-world construction projects.

Practical Construction Units

Convert between feet/meters, square/cubic measurements, weight/load units, material quantities, and construction-specific calculations—everything builders and contractors need.

Industry Standard Calculations

These construction tools are developed using established building codes, engineering standards, and industry-accepted formulas for reliable results in residential and commercial projects.

Construction Safety Disclaimer

These construction calculation tools are for informational, educational, and planning purposes only. They should not replace professional engineering analysis, building code compliance verification, or on-site safety protocols. Always consult licensed professionals for structural and safety-critical projects.

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Board Foot Calculator – Lumber Estimation Guide with Images & Pricing