Lumber Calculator

Calculate board feet and cost for any lumber dimensions.

Lumber Details

Board Feet per Piece
Total Board Feet
Actual Size
Total Cost

How to Calculate Board Feet

Formula: Board Feet (BF) = (thickness × width × length) ÷ 12. All dimensions in inches and feet as marked. Total BF = BF per piece × quantity.

Nominal vs Actual Sizes

NominalActual (inches)
1×23/4 × 1-1/2
1×43/4 × 3-1/2
2×41-1/2 × 3-1/2
2×61-1/2 × 5-1/2
2×81-1/2 × 7-1/4
2×101-1/2 × 9-1/4
2×121-1/2 × 11-1/4
4×43-1/2 × 3-1/2

Note: Board feet are calculated using nominal dimensions, not actual dimensions. This is the standard industry practice for pricing.

FAQ

What is a board foot?
1 BF = 1" thick × 12" wide × 12" long = 144 cu in. Formula: (T × W × L) ÷ 12.
Why is 2×4 not 2×4?
Nominal size is rough-cut green dimension. After drying and planing, 2×4 = 1.5×3.5 inches actual.
Board feet in 2×4×8?
(2 × 4 × 8) ÷ 12 = 5.33 BF per piece. 10 pieces = 53.3 BF.
Lumber cost per BF?
Pine $0.50-1.50/BF, cedar $1.50-3/BF, hardwoods $3-8/BF. Prices fluctuate with market.

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