Board foot calculator
Calculate board feet for lumber purchasing. One board foot = 144 cubic inches (1" x 12" x 12").
Drop calc results into projects and quotes, invoice through your own Stripe, get paid. Built by a contractor.
Try TradeMaster Pro →What Is a Board Foot?
A board foot is the standard unit for measuring and pricing rough lumber. One board foot equals 144 cubic inches — equivalent to a board 1 inch thick, 12 inches wide, and 12 inches long.
The formula is simple: Board Feet = (Thickness x Width x Length) / 144where all dimensions are in inches. For rough lumber, use nominal dimensions. For surfaced lumber (S4S), use actual dimensions for a more accurate volume but nominal for pricing since that's how mills sell it.
Common Board Foot Values
- 1x6x8' = 4 board feet
- 1x12x8' = 8 board feet
- 2x6x8' = 8 board feet
- 2x12x12' = 24 board feet
- 4/4 (1") hardwood: 1 BF per square foot of surface
- 8/4 (2") hardwood: 2 BF per square foot of surface
A board foot equals 144 cubic inches of lumber. The formula is (thickness x width x length) / 12 when length is in feet, or divide by 144 when all dimensions are in inches. Hardwood lumber is almost always sold by the board foot, while softwood framing lumber is typically sold by the linear foot or per piece. Understanding board feet is essential for pricing rough lumber at sawmills and hardwood dealers.
FAQ
How many board feet in a 2x4x8?
(2 x 4 x 8) / 12 = 5.33 board feet. This uses nominal dimensions, which is standard for pricing. Other common values: 2x6x8 = 8 BF, 2x8x10 = 13.33 BF, 2x12x12 = 24 BF.
What's the difference between board foot and linear foot?
Linear foot measures length only — a 10-foot board is 10 linear feet regardless of width or thickness. Board foot measures volume (thickness x width x length). So 1 linear foot of 1x6 = 0.5 BF, while 1 linear foot of 2x12 = 2 BF. Hardwood is sold by the board foot; softwood framing lumber is typically sold by the linear foot or per piece.
How do I calculate board feet for rough sawn lumber?
Use the actual measured dimensions, not nominal. A board measuring 1" x 8" x 10' = (1 x 8 x 120) / 144 = 6.67 BF. For quarter-sawn thickness designations: 4/4 = 1", 5/4 = 1.25", 6/4 = 1.5", 8/4 = 2". Multiply thickness x width x length in inches, then divide by 144.