Board Foot Calculator
Calculate board feet from thickness, width, length, and quantity. Estimate lumber volume and total cost.
Results
- Total board feet
- 40 bd ft
- Board feet per piece
- 4 bd ft
Estimates only. Round up and buy a little extra to account for waste, spills, and breakage.
Hardwood and rough-sawn lumber are sold by the board foot, not by the piece. This board foot calculator converts thickness, width, length, and quantity into total board feet, and prices the order when you enter your mill's rate.
Use nominal dimensions for pricing: a rough 2 × 6 is billed as a full 2 inches thick even after it is planed down.
Also used as a lumber calculator, bd ft calculator, and hardwood board footage estimator.
How to use the board foot calculator
- Enter the thickness in in.
- Enter the width in in.
- Enter the length in ft.
- Enter the number of boards.
- Optionally add a price to estimate the total project cost.
- Read your quantities instantly — no sign-up, and you can print the estimate to take to the supplier.
Worked example
Inputs
- Thickness
- 1 in
- Width
- 6 in
- Length
- 8 ft
- Number of boards
- 10
Results
- Total board feet
- 40 bd ft
- Board feet per piece
- 4 bd ft
Using the example values above, the board foot calculator returns 40 bd ft (total board feet). Change any field to match your own project and the numbers update instantly.
How do you calculate board feet?
One board foot is 144 cubic inches: a board 1 inch thick, 12 inches wide, and 12 inches long. The formula is thickness (in) × width (in) × length (ft) ÷ 12.
A 1 × 6 that is 8 ft long is 4 board feet. A 2 × 4 at 8 ft is 5.33 board feet. Multiply by the piece count for the order total.
Nominal vs. actual lumber sizes
Lumberyards price hardwoods by nominal (rough) size. A board sold as 4/4 (one inch) is really about 13/16 in after surfacing, but you still pay for the full inch. Softwood construction lumber like 2×4s is usually priced per piece instead.
Formula
Board feet = (thickness in × width in × length ft ÷ 12) × quantity.
Frequently asked questions
- What is a board foot?
- A board foot is 144 cubic inches of lumber — for example a 1 in × 12 in × 1 ft board.
- Does board foot use nominal or actual size?
- Use nominal thickness and width (the size before planing) for pricing.
- How many board feet are in a 2x4x8?
- 5.33 board feet: 2 in × 4 in × 8 ft ÷ 12.
- What does 4/4 lumber mean?
- Four-quarter means roughly 1 inch thick rough-sawn. 8/4 is 2 inches, and so on, measured in quarter-inch increments.
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