Calculate board feet, entered-dimension lumber volume, an optional allowance and cost from thickness, width, length and board count.
How to use this tool
- Choose actual measured or seller-supplied billing dimensions.
- Enter thickness, width and length with each unit selected. Fractional inch values are accepted.
- Enter the count of identical boards, an optional allowance and your optional price per board foot.
- Select Calculate. Read net quantity separately from quantity with allowance, and confirm the seller’s tally rules.
Formula and unit basis
BF = thickness(in) × width(in) × length(ft) × count ÷ 12. One board foot is exactly 144 in³, or 0.002359737216 m³.
Worked examples
Five boards, each 1.25 in × 10 in × 8 ft, contain 41.666667 BF on the entered dimension basis. At a hypothetical 4.15 per BF, cost is about 172.92 before other charges.
Assumptions and interpretation
The calculation uses the dimensions you enter. It does not apply a seller’s minimum thickness, tally rounding, nominal-to-actual conversion, grading or log-scale rules. An allowance increases quantity and estimated cost; it is not a cutting-layout optimiser.
Project guides
- Buying Hardwood by the Board Foot: Rough Thickness, Surfacing and Billing
- From Furniture Cut List to Lumber Order: Yield, Kerf and Offcuts
Choose the related tool for the next question
Explore Construction calculators or return to the GreenCalc home page for other subjects.
Frequently asked questions
Does this calculator apply lumberyard billing rules?
No. Select the dimension basis and enter the corresponding values. The tool does not silently round thickness, width or tally quantities.
Is a board foot an area?
No. It is a volume of 144 cubic inches, equivalent to one square foot at one inch thick.
What does the allowance change?
It increases the entered total quantity and estimated cost by your chosen percentage; it does not create a cutting layout.