CalculateY
Quick Answer
A standard 1-inch by 12-inch by 96-inch board (a nominal 1x12 eight feet long) contains 8 board feet.
Common Examples
| Input | Result |
|---|---|
| 1" x 12" x 96" (1 piece) | 8 BF |
| 2" x 6" x 96" (1 piece) | 8 BF |
| 1" x 8" x 120" (10 pieces) | 6.67 BF/piece, 66.67 BF total |
| 2" x 4" x 96" (20 pieces) | 5.33 BF/piece, 106.67 BF total |
| 4" x 6" x 144" (5 pieces) | 24 BF/piece, 120 BF total |
How It Works
The Formula
The board foot is the standard unit of measure for hardwood lumber in the United States and Canada:
Board Feet = (Thickness x Width x Length) / 144
Where all dimensions are in inches. The divisor 144 converts cubic inches to board feet (since 1 board foot = 12” x 12” x 1” = 144 cubic inches).
If the length is measured in feet instead of inches, the formula simplifies to:
Board Feet = (Thickness x Width x Length in feet) / 12
For multiple pieces of the same size, multiply the board feet per piece by the quantity.
What Is a Board Foot?
A board foot is a unit of volume equal to 144 cubic inches of wood. It represents a piece of lumber 1 inch thick, 12 inches wide, and 1 foot long. This unit is used primarily for pricing and measuring rough-sawn hardwood lumber. Softwood lumber (construction framing) is typically sold by the linear foot, but hardwood and specialty wood are almost always priced per board foot.
Nominal vs. Actual Dimensions
When buying lumber, nominal dimensions (what the board is called, like “2x4”) differ from actual dimensions after milling and drying. A nominal 2x4 actually measures 1.5” x 3.5”. For board foot calculations at the sawmill or when buying rough-sawn lumber, use the actual measured dimensions. For estimating purposes with surfaced lumber, using nominal dimensions gives a conservative (slightly high) estimate.
Lumber Pricing
Hardwood lumber is priced per board foot. For example, if red oak costs $6.50 per board foot and a project requires 40 board feet, the lumber cost would be $6.50 x 40 = $260. This pricing method accounts for the actual volume of wood, making it fair for boards of varying widths and lengths.
Worked Example
For a board that is 2 inches thick, 6 inches wide, and 96 inches long: Board Feet = (2 x 6 x 96) / 144 = 1,152 / 144 = 8 BF. For 20 such pieces: 8 x 20 = 160 total board feet. At a price of $5.00 per board foot, that would cost $800. For a 1-inch by 8-inch by 120-inch board: BF = (1 x 8 x 120) / 144 = 960 / 144 = 6.67 BF per piece.