Board Foot Calculator
Estimate lumber volume and cost so you can compare quotes and plan your project before you buy.
- 2026 figures, checked October 26, 2026
- Private: runs in your browser
- How we check our work
Result
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Updated as you type, from your inputs only. General information, not personal advice; confirm any change with a qualified professional.
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What is a board foot?
A board foot is a way to describe lumber volume. The Board Foot Calculator uses thickness, width, length, and piece count to estimate how much lumber a project requires.
The result helps you compare material quantities and prices on a consistent basis. Use the dimensions that match the lumber quote, and confirm with the seller how the lumber is measured.
Why board feet matter
Lumber may be quoted by the board foot, by the piece, or in another way. Knowing the board-foot total helps you compare quotes and estimate material cost using the quoted price per board foot.
A volume estimate also helps you plan purchases and spot measurement errors before placing an order. It does not account for cuts, defects, or project-specific waste, so review the result alongside your plans and the seller’s order details.
How to use this board feet calculator
- Enter the lumber thickness in inches.
- Enter the width in inches and length in feet.
- Enter the number of pieces you plan to buy.
- Enter the quoted price per board foot if you want to estimate material cost. If you leave the price at 0, the price-based estimate will be zero; that does not mean the lumber is free.
- Review the board feet per piece and total board feet. Compare the quantity with your plans and the supplier’s quote.
Board foot calculator example
Worked example
Enter Thickness (in) 2, Width (in) 6, Length (ft) 8, Pieces 10, and Price per board foot 0. The calculator reports Board feet: 80, with 10 pieces. It shows 2" x 6" x 8', Board feet each: 8, and Total board feet: 80.
How to read your board feet result
The calculator applies this formula: thickness (in) × width (in) × length (ft) ÷ 12. That gives board feet for one piece. The total reflects the number of pieces entered.
For a cost estimate, multiply total board feet by the price per board foot from your quote. Check that the quote uses the same measurement basis and dimensions as your calculation. Ask the supplier to clarify any difference before you order.
How to make your lumber estimate more useful
- 01
Measure the material you are actually buying
Use the dimensions shown on the quote or confirmed by the seller. If your plans list different dimensions, ask whether those refer to nominal or actual measurements before comparing totals.
- 02
Check piece counts against your cut list
List the required pieces and lengths, then compare that list with the quantity entered. Update the calculator when your design or order changes.
- 03
Compare quotes on the same basis
Use the quoted price per board foot with the calculated total. If suppliers quote in different units, ask each supplier to provide a comparable quantity and price before choosing.
- 04
Review the plan for unusable material
Consider how cuts, defects, and project requirements may affect the amount you can use. Adjust your order based on the actual project plan and confirm the quantity with your supplier.
Common board foot calculator mistakes
Mixing units
The calculator expects thickness and width in inches and length in feet. Convert measurements before entering them if your plans use other units.
Entering dimensions from memory
A small measurement error can change the estimated volume. Check the quote, product details, or your project measurements before relying on the result.
Confusing volume with project coverage
Board feet measure lumber volume, not the area a finished surface will cover. For a project estimate, account for the specific pieces and cuts in your plan.
Treating the estimate as a final order
The result does not include project-specific waste or confirm stock availability. Check your cut list and order details with the seller.
The board feet formula
Board feet = thickness (in) x width (in) x length (ft) / 12.
Key terms
- Board foot
- A lumber-volume measure calculated here from thickness in inches, width in inches, and length in feet.
- Board feet per piece
- The estimated board-foot volume of one piece using the entered dimensions.
- Total board feet
- The estimated volume for all entered pieces.
- Price per board foot
- The quoted lumber price for each board foot, used to estimate material cost.
Board feet questions
How do I calculate board feet by hand?
Multiply thickness in inches by width in inches by length in feet, then divide by 12. For multiple pieces, account for the piece count to get the total.
How do I estimate lumber cost from board feet?
Multiply the total board feet by the supplier’s price per board foot. Confirm that the quote and calculator use the same dimensions and measurement basis.
Why might my result differ from a supplier’s quote?
The supplier may be using different dimensions, piece counts, or measurement conventions. Ask for the dimensions and quantity behind the quote, then enter matching values.
Before you act on this result. Cordwell calculators and guides are educational estimates, not legal, tax, investment, lending or other professional advice. They rely on the numbers you enter and on simplified rules, and they can't see your full situation. Before you file, sign, borrow, invest, hire, change your withholding or form a business based on anything here, meet with a licensed contractor, engineer or the local building department who can review your specific facts and confirm the numbers. Rules change, and official agency guidance always controls.