Enter Board Dimensions
Calculation Result
Results are estimates based on the dimensions entered.
What Is a Board Foot?
A board foot is a standard unit for measuring lumber volume. One board foot represents a piece of wood 12 inches long, 12 inches wide, and 1 inch thick. It equals 144 cubic inches or one-twelfth of a cubic foot.
Lumberyards, carpenters, woodworkers, furniture makers, and timber businesses use board footage to estimate the amount of wood in boards with different dimensions. Unlike square footage, board footage measures volume and includes thickness.
How to Calculate Board Feet
Multiply thickness in inches by width in inches and length in feet. Divide the product by 12 to calculate the board footage of one rectangular board.
Board Feet = Thickness × Width × Length ÷ 12
For example, a board measuring 1 inch thick, 6 inches wide, and 8 feet long contains 4 board feet. Five identical boards contain 20 board feet. This calculator converts alternative length units into feet before applying the formula. Thickness and width must be entered in inches.
Board Foot Calculation Examples
| Thickness | Width | Length | Board Feet |
|---|---|---|---|
| 1 in | 6 in | 8 ft | 4 |
| 2 in | 6 in | 8 ft | 8 |
| 1 in | 12 in | 10 ft | 10 |
| 1.5 in | 3.5 in | 8 ft | 3.5 |
| 2 in | 4 in | 10 ft | 6.67 |
These examples use the exact dimensions shown. Actual board footage can differ when a board’s physical size differs from its nominal dimensions.
Actual Size vs. Nominal Lumber Size
Lumber is often sold using nominal dimensions such as 2 × 4 or 2 × 6. These labels do not necessarily match finished dimensions. A typical surfaced 2 × 4 measures approximately 1.5 inches thick and 3.5 inches wide.
For physical volume estimates, measure the actual board. If a supplier quotes prices using nominal dimensions or another convention, confirm that method before comparing costs.
Why Use a Board Foot Calculator?
Calculating each board manually can be time-consuming when preparing a lumber order. This tool calculates the volume per board and the combined footage for multiple identical boards. It can help with preliminary material estimates for shelves, tables, cabinets, doors, frames, and other woodworking projects.
Board footage does not determine wood grade, structural suitability, moisture content, or material quality. Consider these factors separately when choosing lumber.
Estimate Lumber Cost
Multiply the total board footage by the quoted price per board foot to estimate material cost. For example, 20 board feet at $5 per board foot gives an estimated cost of $100 before taxes, delivery, waste, and additional fees.
Prices vary by species, grade, dimensions, location, and supplier. Confirm the supplier’s measurement and pricing method before ordering.
Tips for Accurate Results
- Enter thickness and width in inches.
- Select the correct length unit.
- Enter a whole number for board quantity.
- Measure actual dimensions for physical-volume estimates.
- Calculate different board sizes separately.
- Confirm supplier measurement and rounding rules.
This calculator is designed for rectangular boards. Irregular logs, tapered timber, curved pieces, and sawmill yield may require different measurement methods. Treat the result as an estimate and confirm the applicable measurement standard with your supplier.
Frequently Asked Questions
Answers to common questions about board feet and lumber calculations.
What is the formula for board feet?
Multiply thickness in inches by width in inches and length in feet, then divide by 12. Multiply the result by the quantity for multiple identical boards.
How many board feet are in a 2 × 4 × 8 board?
Using nominal dimensions, 2 × 4 × 8 ÷ 12 equals approximately 5.33 board feet. Using typical actual dimensions of 1.5 × 3.5 × 8 gives 3.5 board feet. The result depends on the measurement convention.
Can I calculate multiple boards at once?
Yes. Enter the dimensions of one board and the number of identical boards. The calculator multiplies the per-board volume by the quantity.
Can I enter length in meters or centimeters?
Yes. Choose meters, centimeters, inches, or feet from the length-unit menu. The calculator converts the length to feet internally. Thickness and width must remain in inches.
How many cubic inches are in one board foot?
One board foot equals 144 cubic inches. To convert board feet into cubic feet, divide by 12. For example, 12 board feet equal 1 cubic foot.
Is a board foot the same as a square foot?
No. A square foot measures area, while a board foot measures volume. Board footage includes thickness, width, and length.
Does the calculator use actual or nominal dimensions?
It uses the dimensions you enter without automatically changing them. Use actual dimensions for physical-volume estimates or nominal dimensions when that is the required pricing convention.
How do I estimate lumber cost?
Multiply total board feet by the supplier’s price per board foot. The result estimates material cost before taxes, delivery, waste, and other charges.
Results are rounded for display. Supplier measurement standards may vary.