Lumber & framing calculator
Board foot calculator
Lumber board-foot quantity from stated thickness, width, length, piece count and allowance.
Calculator result and formula
Planning board footage: 110 board ft
Formula: Thickness (in) × width (in) × length (ft) × quantity ÷ 12 × (1 + waste)
Formula ID: LUM-BF-001 · Version 1.0.0.
Inputs
- Lumber thickness: Use the pricing thickness basis supplied by the lumber seller Default: 2.
- Lumber width: Use the pricing width basis supplied by the lumber seller Default: 6.
- Board length: Length of one board Default: 10.
- Number of boards: Count identical boards Default: 10.
- Waste factor: Allowance for defects, cuts and selection Default: 10.
How this calculator works
This calculator applies the standard board-foot volume formula to stated lumber dimensions and piece count, keeping its purchase allowance visible.
- Use the thickness and width basis used by the seller for pricing.
- Enter board length and count for identical pieces.
- Add a documented allowance for selection, defects or cuts before obtaining supplier pricing.
Worked example: Example: ten 2 in × 6 in × 10 ft boards contain 100 board feet before a 10% allowance, resulting in 110 planning board feet.
Assumptions and limitations
- Board-foot arithmetic uses the stated thickness and width pricing basis, not an assumed nominal or actual size.
- Metric dimensions are converted to inches before the board-foot formula.
- Waste is a transparent planning allowance and supplier tally rules can differ.
Common questions
- Does this choose nominal or actual lumber sizes?
- No. Enter the measurement basis used by the seller; nominal and actual dimensions serve different planning purposes.
- Does board footage determine structural suitability?
- No. Board-foot arithmetic is a volume calculation, not lumber-grade, span or structural design approval.
Reference notes
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