How this site is built
Review the calculation methodology to see which figures are exact geometry, which depend on material assumptions, and which figures have recorded sources. The source registry records every cited figure and its review status.
How the board foot calculator works
A board foot is a trade volume of 144 cubic inches. With thickness and width in inches and length in feet, divide their product by 12 and multiply by quantity.
Use nominal dimensions for board-foot pricing unless the seller explicitly prices another basis. Actual dressed dimensions are smaller.
Formula used for board foot calculator
The calculator keeps the measured quantity separate from any purchase rounding or allowance.
- One piece
board feet = thickness(in) × width(in) × length(ft) ÷ 12 - Order
total = board feet per piece × quantity
Planning choices for board foot calculator
| Situation | Use | Why it matters |
|---|---|---|
| Dimensional lumber pricing | Use nominal size | Matches the trade convention |
| Rough-sawn exact stock | Confirm seller basis | Nominal and measured may coincide |
| Finished volume needed | Use actual dimensions | Board-foot billing is not physical finished volume |
These are measurement and ordering choices, not structural specifications or code requirements.
Measure and order board foot
Enter the billed nominal thickness and width, then the full piece length. Add species, grade and price outside the volume calculation.
Do not use board feet to size a structural member or substitute one grade or species for another. It is a quantity unit only.
Board Foot Calculator questions
What is one board foot?
It is exactly 144 cubic inches, commonly pictured as 1 in × 12 in × 1 ft.
Why use nominal dimensions?
Board-foot pricing convention commonly uses nominal size, even though dressed lumber is smaller.
Is a 2 × 4 × 8 equal to 5.33 board feet?
Yes on nominal dimensions: 2 × 4 × 8 ÷ 12 = 5.333 board feet.
Variables and units
For the default “Dimensional lumber” mode. Other modes label their own fields in the calculator.
thickness- Nominal thickness: in.
width- Nominal width: in.
length- Length per piece: ft.
quantity- Number of pieces: unitless.
Worked example: twelve nominal 2 × 8 × 10 boards
A lumber order has twelve pieces, each nominally 2 in thick, 8 in wide and 10 ft long.
| Field | Value |
|---|---|
| Nominal thickness | 2 in |
| Nominal width | 8 in |
| Length per piece | 10 ft |
| Number of pieces | 12 |
| Result | Value |
|---|---|
| Total board feet | 160 bd ft |
| Board feet per piece | 13.3 bd ft |
These figures are generated by the same calculation the calculator above uses, so they update automatically if the method changes.
Where these numbers come from
| Assumption | Value used |
|---|---|
| Volume of one board foot.A board foot is defined as 144 cubic inches: 1 inch thick by 12 inches wide by 1 foot long. Lumber is billed on nominal dimensions, so use the nominal size when pricing. Applicability: A mathematical or trade definition used consistently by the current calculators; not a market-specific measured property. | 144 in³ |
Sources
- Construction trade unit conventions (roofing square, board foot): Long-standing trade convention
Content release:
Published by Material Totals. Review the methodology and source assumptions.
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