Board Foot Calculator
Quickly compute board feet for rough lumber with professional accuracy. Designed for contractors, mill operators, and woodworkers, this tool calculates board feet from thickness, width, length, and quantity, supports metric and imperial inputs, and can add waste and pricing to produce reliable estimates.
Calculator
Results
Additional breakdown
Data Source and Methodology
Authoritative standard: National Hardwood Lumber Association (NHLA), Rules for the Measurement & Inspection of Hardwood & Cypress Lumber, 2019 Edition. See “Measurement” and the definition of the board foot (1 BF = 144 in³). Link: https://nhla.com/rulesbook/.
Tutti i calcoli si basano rigorosamente sulle formule e sui dati forniti da questa fonte.
The Formula Explained
Imperial inputs (thickness and width in inches, length in feet):
\\[ \\text{Board Feet (BF)} = \\frac{T_{in} \\times W_{in} \\times L_{ft}}{12} \\]
With length in inches instead of feet:
\\[ \\text{BF} = \\frac{T_{in} \\times W_{in} \\times L_{in}}{144} \\]
Metric inputs (thickness and width in millimeters, length in meters):
\\[ \\text{BF} = \\frac{T_{mm} \\times W_{mm} \\times L_{m}}{2359.737216} \\quad \\text{since} \\quad 2359.737216 = 25.4^2 \\times 12 \\times 0.3048 \\]
Conversions: \\(1\\,\\text{BF} = 144\\,\\text{in}^3 = 1/12\\,\\text{ft}^3 \\approx 0.002359737\\,\\text{m}^3\\).
Glossary of Variables
- Thickness (T): Board thickness. Inputs: inches (imperial) or millimeters (metric).
- Width (W): Board width. Inputs: inches (imperial) or millimeters (metric).
- Length (L): Board length. Inputs: feet (imperial) or meters (metric).
- Quantity (Qty): Number of identical boards of the given dimensions.
- Board Feet (BF): Volume measure for lumber; total BF is summed across rows.
- Waste Factor (%): Percentage added to total BF for defects, trimming, and selection.
- Price per BF: Unit price used to estimate total material cost.
Come Funziona: Un Esempio Passo-Passo
Suppose you need four boards, each 2 in thick, 8 in wide, and 10 ft long. Set quantity to 4, waste to 10%, and price to $5.50/BF.
- Per-board board feet: using \\( \\text{BF} = \\frac{2 \\times 8 \\times 10}{12} = 13.333\\,\\text{BF} \\).
- Total before waste: \\( 13.333 \\times 4 = 53.333\\,\\text{BF} \\).
- Apply waste: \\( 53.333 \\times 1.10 = 58.666\\,\\text{BF} \\).
- Estimated cost: \\( 58.666 \\times 5.50 \\approx \\$322.66 \\).
Frequently Asked Questions (FAQ)
Is nominal size (e.g., 2×4) the same as actual size?
No. Rough-sawn may be close to nominal, but planed (surfaced) lumber is smaller. Always use actual dimensions for accurate board feet.
Can I mix imperial and metric inputs?
For consistency and fewer mistakes, the tool uses one system at a time. Switch units to metric or imperial, and the calculator will convert internally.
How precise are the results?
Calculations are performed in double precision and rounded for display. You can change decimal precision by exporting and rounding externally if needed.
What about volume in cubic feet or cubic meters?
The results panel shows both: ft³ is BF ÷ 12; m³ uses 1 BF ≈ 0.002359737 m³.
What waste factor should I use?
Choose 5–15% for typical hardwood projects; adjust higher for heavy defect trimming, selective color matching, or short yield boards.
Does this include tax or cutting fees?
No. The cost estimate multiplies waste-adjusted BF by your unit price. Add taxes, milling, and delivery separately.
Is this method accepted in industry?
Yes. The board foot definition and measurement approach follow NHLA guidelines and common North American practice.