Board Foot Calculator
Convert lumber dimensions into board feet and total cost.
What you'll need to order
- dimensional lumber
- hardwood boards
Prices vary by region and haul distance. Get quotes from at least two local suppliers.
How this calculator works
board feet = thickness (in) × width (in) × length (ft) ÷ 12
A board foot is a volume, not an area: 144 cubic inches. Hardwood is priced this way, softwood usually by the linear foot or piece, which is why the two are hard to compare directly.
Worked example
With thickness 1 in, width 6 in, length 8 ft, number of boards 1 , this calculator returns 4 .
Board feet by lumber width
Figures below assume thickness 1 in × length 8 ft × number of boards 1 . Change any measurement in the calculator to get your own numbers.
| Width | Board feet per piece | Total linear feet (ft) |
|---|---|---|
| 4 in | 2.67 | 8.00 |
| 6 in | 4.00 | 8.00 |
| 8 in | 5.33 | 8.00 |
| 10 in | 6.67 | 8.00 |
| 12 in | 8.00 | 8.00 |
One-inch nominal boards, 8 ft long. A board foot is 144 cubic inches — one square foot of one-inch stock.
Board feet for common lumber orders
| Job | Size | Board feet |
|---|---|---|
| 1x6 pine, 10 boards | 1 in × 6 in × 8 ft × 10 | 40.00 |
| 2x4 framing, 50 pieces | 2 in × 4 in × 8 ft × 50 | 266.7 |
| 2x6 joists, 20 pieces | 2 in × 6 in × 12 ft × 20 | 240.0 |
| 4/4 walnut for a table top | 1 in × 8 in × 8 ft × 6 | 32.00 |
| 8/4 maple for legs | 2 in × 6 in × 6 ft × 4 | 24.00 |
| 1x12 shelving, 8 boards | 1 in × 12 in × 10 ft × 8 | 80.00 |
Hardwood is priced by the board foot, softwood framing usually by the piece. Both are quoted on nominal size, not the dressed dimension you measure.
Hardwood thickness in quarters
| Type | Nominal thickness (in) | Notes |
|---|---|---|
| 4/4 ("four quarter") | 1.00 | Dresses to 13/16 in; the default stock |
| 5/4 | 1.25 | Stair treads, thick shelving |
| 6/4 | 1.50 | Table aprons, heavy frames |
| 8/4 | 2.00 | Legs and structural furniture parts |
| 12/4 | 3.00 | Turning blanks, heavy timber |
Quarters express thickness in quarter-inches before drying and planing. Board foot pricing always uses that nominal figure, which is why 4/4 stock measures 13/16 in but bills as a full inch.
Frequently asked questions
How many board feet in a 2x4x8?
Five and one third. Thickness times width times length in feet, divided by 12: 2 × 4 × 8 ÷ 12 = 5.33 board feet.
How much does a board foot of lumber cost?
Softwood construction lumber runs $1 to $3 per board foot. Domestic hardwoods span $4 to $12, and figured or imported species go well beyond that.
How many board feet in a linear foot?
It depends on the board. A 1x6 gives half a board foot per linear foot; a 2x8 gives 1.33. Multiply thickness by width in inches and divide by 12.
What is a board foot?
A volume equal to 144 cubic inches — one inch thick, twelve inches wide and one foot long. It is how hardwood lumber is priced, regardless of the actual board dimensions.
How do I calculate board feet?
Multiply thickness in inches by width in inches by length in feet, then divide by 12. A 2 by 12 board 16 ft long contains 32 board feet.
Should I use nominal or actual dimensions?
For rough sawn hardwood, use the nominal thickness — a 4/4 board measures a full inch before surfacing. For surfaced softwood, a "2x4" actually measures 1.5 by 3.5 inches, and using nominal figures overstates volume by 40%.
Why is hardwood sold by the board foot?
Hardwood comes in random widths and lengths straight off the mill, so pricing by volume is the only fair measure. Softwood is milled to standard sizes, which is why it can be priced per piece.