Board Foot Calculator

Thickness (in inches): Example: 1 (for 1 inch thick)

Width (in inches): Example: 6 (for 6 inches wide)

Length (in feet): Example: 8 (for 8 feet long)

Quantity (number of boards): Example: 2

Calculate

Board Foot Calculator: Accurate Lumber Estimation Made Easy

Whether you’re a weekend woodworker or a professional carpenter, knowing exactly how much lumber you need can save time and money. The Board Foot Calculator provides a simple way to measure wood volume, allowing you to estimate costs and plan projects more effectively. By converting the thickness, width, length, and quantity of boards into a single “board foot” value, you gain clear insight into the total amount of material required for cabinetry, flooring, fence posts, or any other woodworking project.

How to Use the Board Foot Calculator

Our Board Foot Calculator is designed with simplicity and precision in mind. Follow these steps to get a reliable result:

1. Enter Thickness (in inches): Measure the thickness of your board as accurately as possible. Common thicknesses include 1″, 2″, or ¾”. This figure represents the vertical dimension of the board when laid flat.
2. Enter Width (in inches): Measure the width of the board’s face. Standard widths often range from 4″ to 12″, but you can work with any precise measurement.
3. Enter Length (in feet): Measure how long each board is. Length should be entered in feet, making it easier to calculate board feet since length is often sold in whole feet—such as 8′, 10′, or 12′.
4. Enter Quantity (number of boards): Specify how many identical boards you plan to use. If you’re working with multiple pieces of the same dimensions, the calculator will multiply the board-foot value accordingly.
5. Click “Calculate”: Your total board-foot requirement appears immediately. For example, a single board measuring 1″ thick, 6″ wide, and 8′ long equates to 4 board feet. If you have two boards of that size, the total would be 8 board feet.

Once you have your final board-foot number, you can contact suppliers with confidence or compare prices across different lumberyards. The “Share,” “Print,” and “Download” options help you keep a clear record or show your estimate to team members on the job site.

Looking for more handy tools? Explore our complete set of calculators to assist in everything from construction costs to personal finance.

Why Board Foot Measurement Is Essential

The concept of a “board foot” is unique to the woodworking and lumber industries. One board foot equals the volume of a board that measures 1 inch thick, 12 inches wide, and 12 inches long. Calculating board feet brings consistency to purchasing and pricing because lumber prices are often quoted per board foot rather than by piece or linear foot. By using this standardized measure, you avoid guesswork and ensure you never order too little—or too much—material.

For deeper insight into board foot conversions, refer to this authoritative resource from The Wood Database. That guide covers edge cases like irregular shapes and specialty cuts.

Understanding the Board Foot Formula

At its core, the board foot formula is straightforward:

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

Here’s why the formula works:

• Thickness × Width: Multiplying these gives you square inches of face area.
• Length in Feet: When length is expressed in feet, multiplying by square inches yields cubic feet—except for the fact that a board foot is defined as 1″ × 12″ × 12″, which is equal to 144 cubic inches or 1/12 of a cubic foot.
• Divide by 12: This adjustment converts from cubic inches to board feet. Dividing the product by 12 ensures that 1 board foot equals 144 cubic inches (1″ × 12″ × 12″).

For example, a 2″ × 8″ × 10′ board yields:

(2 × 8 × 10) ÷ 12 = (160) ÷ 12 = 13.33 board feet (rounded to two decimals).

If you have three of these boards, multiply 13.33 by 3 to get 40 board feet total.

Frequently Asked Questions

1. Why can’t I simply buy lumber by linear feet?

Buying by linear foot only accounts for length, not thickness or width. A 1″ × 4″ × 8’ board is very different from a 2″ × 12″ × 8’ board, even though both are 8 feet long. Board feet standardize volume so that you don’t end up with insufficient material once you begin cutting or building.

2. Does the calculator work for irregular shapes, like live-edge slabs?

Live-edge slabs often have uneven edges, making precise board-foot measurement more complex. For those, you may need to average width measurements at various points or consult a lumber specialist. Our calculator is optimized for rectangular, uniform boards.

3. What unit conversions should I keep in mind?

This calculator uses inches for thickness and width, and feet for length—because that matches how most lumber is measured and sold. If you have a metric supply, convert millimeters to inches (1 inch = 25.4 mm) and meters to feet (1 meter ≈ 3.281 ft) before using the tool.

4. Can I estimate the cost of lumber using my board-foot total?

Absolutely. Lumberyards often list prices per board foot. Once you know your total board feet, multiply by the price per board foot to get a reliable cost estimate. Keep in mind that specialty species like walnut or cherry typically sell at higher rates than pine or fir.

5. Does wood shrink or expand affect board-foot calculations?

Wood does expand and contract with humidity. The board foot calculation assumes nominal (standard) dimensions. For precise joinery or fine woodworking, account for seasonal expansion by purchasing slightly more board feet than the calculated amount. Professional woodworkers sometimes add 10% extra to cover waste, mistakes, and moisture-related changes.

6. How do I handle off-cuts and waste?

Planning for waste is critical. Even careful cuts leave sawdust and off-cuts. A common practice is to add 5–10% extra board feet to your order to account for waste. If you’re working with expensive hardwoods, minimize waste by planning cuts meticulously and using software or templates to optimize board layout.

7. Can I use this calculator for plywood or sheet goods?

Plywood and other sheet goods are typically sold by the sheet, not by board foot. However, if you need to know the volume in board feet, you can convert sheet dimensions (e.g., 4′ × 8′ × ¾”) into board feet by first converting all measurements to the calculator’s format. In most cases, it’s simpler to purchase sheet goods by the sheet and calculate cost by square footage.

Explore More Tools

Interested in other construction- and woodworking-related calculators? Check out our Construction Tools Collection for everything from drywall estimators to cost-per-square-foot calculators.

For a detailed guide on lumber purchasing and board foot calculations, visit Wood Magazine’s lumber buying guide. That resource covers advanced topics like moisture content, grading, and specialty cuts.

Conclusion

Accurate lumber estimation is the foundation of any successful woodworking project. Using the Board Foot Calculator helps you dial in your material requirements, minimize waste, and avoid costly last-minute trips to the lumberyard. Armed with the confidence of precise board-foot measurements, you can focus on craftsmanship rather than worry about running out of material. Try the calculator today, and take one more step toward project efficiency and cost savings.

Disclaimer

The estimates provided by this Board Foot Calculator are for general guidance only. Actual yield may vary based on wood species, moisture content, milling tolerances, and waste from cutting. Always consult with your lumber supplier or a professional woodworker for exact measurements and pricing before making large purchases.