Board Foot Calculator
Calculate lumber volume in board feet (BF) instantly. The professional standard for precision woodworking, hardwood estimation, and high-volume timber procurement.
Result in Board Feet (BF)
1 BF = 144 Cubic Inches (12" x 12" x 1")
The Volume of Wood
Unlike linear feet (length) or square feet (surface), a board foot** is a measure of total volume. It is the industrial standard for calculating cost in the timber trade because it accounts for the thickness of the material-ensuring a 2-inch thick plank is priced correctly compared to a 1-inch board of the same length and width.
Whether you are a professional luthier selecting instrument-grade maple or a framing contractor ordering a lift of 2x4s, understanding BF is the first step in project budgeting.
Trading Tall Timber
Sawmill Origins
The board foot became the standard in North American sawmills during the 19th century to simplify how rough-cut logs were valued before being planed into finished lumber.
Standard Unit
Defined mathematically as 144 cubic inches, it allows buyers to compare the "useful wood" content across boards of wildly different shapes and sizes.
The Volume Unit: 1 BF
Visualize a board that is exactly 12 inches wide, 1 foot long, and 1 inch thick. This single chunk of wood represents 1 board foot.
Quarters (4/4, 5/4, 8/4)
Hardwood is often sold by "quarters." 4/4 is roughly 1-inch thick, 8/4 is 2-inches thick, and so on. Always use the quarter-thickness for your BF calculations.
Calculation Method
LUMBER EQUATION
BF = (T" × W" × L') / 12
Step-by-Step Guide
1Measure thickness (T) in inches and width (W) in inches.
2Measure length (L) in feet (be careful not to use inches for length here).
3Multiply T × W × L and divide by 12 for your final Board Feet.
Visualization Tip
One Board Foot is the size of a standard thick hardcover textbook laid flat on a desk. If you are building a dining table, you'll likely need between 50 and 80 "textbooks" worth of oak or walnut.
Expert Lumber Buying Tips
- Measure Width at the Narrowest Point
- Accounts for Board Defects and Checks
- Subtract knot holes from total volume
- Use Nominal sizes for softwood/framing lumber
- Use Quarter dimensions (4/4, 8/4) for hardwood prices
Beyond Simple Square Feet
In the flooring and cabinetry industries, standard square feet work because the material is a uniform thickness. However, when buying raw logs or custom-milled slabs, thickness varies wildly. The Board Foot system ensures you pay only for the total "wood fiber" you are actually receiving.
Common Lumber Reference Table
Nominal Size Length Board Feet (BF) 1 x 6 8 ft 4.00 BF 1 x 8 10 ft 6.67 BF 2 x 4 8 ft 5.33 BF 2 x 6 10 ft 10.00 BF 2 x 8 12 ft 16.00 BF 4 x 4 8 ft 10.67 BF Visualizing Wood Volume
Small Wood Box
2 Board Feet
Jewelry box scale
Guitar Neck Blank
3 Board Feet
Standard electric neck
Coffee Table Top
15 Board Feet
Rough walnut slab
Sideboard Cabinet
45 Board Feet
Includes shelving
Standard Deck Joist
12 Board Feet
Based on 2x8x10
Dining Table (Oak)
75 Board Feet
Heavy artisan scale
Frequently Asked Questions