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Linear Feet to Board Feet Converter

Convert a run of linear feet at a nominal thickness and width into board feet.

Linear feet to board feet
Enter nominal thickness and width in inches, the linear run, and how many pieces.

Fills thickness and width only. Linear feet and quantity stay as entered.

Board and run
in

Nominal inches (use 1 for a 1x6, not 0.75).

in

Nominal inches (use 6 for a 1x6, not 5.5).

ft

Length of the run per piece. Switch to inches if that is how you measured.

pcs

Number of identical pieces or runs.

Total board feet

4 bd ft

Per piece: 4 bd ft

What is the difference between linear feet and board feet?

Linear feet measure length; board feet measure volume.

Linear feet describe how far a board runs, end to end, and ignore its thickness and width. Board feet describe how much wood the board contains: thickness times width times length. Two boards can share the same linear footage and hold very different amounts of wood. A 1x6 and a 2x12 that each run 8 feet are both 8 linear feet, but the 2x12 is four times the board footage.

You convert linear feet to board feet whenever a run of known size needs a volume figure, most often for pricing or a cut list. Suppliers commonly stock and sell by the piece or the linear run, while volume pricing and MBF quotes are stated in board feet. Enter the nominal thickness and width, the length of the run, and how many identical pieces you have.

As with any board-foot tally, the nominal size drives the math: use the stamped size (1x6), not the dressed size (about 0.75 by 5.5 inches), unless you are measuring custom stock and want its true volume.

How to convert linear feet to board feet

The board-foot identity, which size to enter, and how the result rounds.

Formula

board feet = (thickness in × width in × linear ft × quantity) ÷ 12

How the formula works

Board feet = (thickness in inches x width in inches x linear feet x quantity) / 12. Linear feet are already a length in feet, so they drop straight into the board-foot identity with no extra conversion. Thickness times width is in square inches, times the run in feet gives inch-inch-feet, and dividing by 12 converts the width from inches to feet so the answer lands in board feet. This is the same rule as DOC PS 20 board measure. If you measured the run in inches, switch the length unit and the tool divides by 12 before applying the formula.

Which size to enter

  • Enter nominal sizes for standard softwood (a 1x6 is 1 by 6), not dressed sizes, unless you are measuring surfaced or custom stock and want its actual volume.
  • Board measure in the American Softwood Lumber Standard uses nominal thickness and width; cubic measure uses dressed sizes. This tool reports board measure.
  • Mixed feet and inches, such as 8 ft 6 in, should be entered as 8.5 ft or 102 in.

Rounding

The live total is the exact formula result; the display uses up to two decimals, standard for a DIY tally. Quantity multiplies identical pieces or runs, and waste, kerf, and grade loss are not added automatically. Suppliers may tally and round by their own rules at the line-item or order level, so treat this as a check figure rather than an invoice.

Example

One 1x6, an 8 ft run (nominal sizes):
  1. 1
    Thickness × width × linear ft1 in × 6 in × 8 ft = 48
  2. 2
    Divide by 1248 ÷ 12 = 4 bd ft per piece
  3. 3
    Multiply by quantity4 × 1 = 4 bd ft total
Result4 bd ft

FAQ

Practical answers for converting a linear run into board feet.

What is the difference between linear feet and board feet?

Linear feet measure length only: a 1x6 that runs 8 feet is 8 linear feet regardless of how wide it is. Board feet measure volume: thickness times width times length. Two boards can share the same linear footage but differ in board feet if their thickness or width differ. Lumber sold by the piece or by the run is often listed in linear feet, while pricing by volume uses board feet.

How do I convert linear feet to board feet?

Multiply nominal thickness in inches by nominal width in inches by the linear feet, then divide by 12. For several identical pieces, multiply by the quantity. This is the same board-foot identity used for lumber tally in DOC PS 20: one board foot is 144 cubic inches of nominal volume, and dividing by 12 converts the inch-inch-feet product into board feet.

Should I use nominal or actual dressed size?

For buying standard softwood, use the nominal size printed on the grade stamp: a 1x6 is tallied as 1 inch by 6 inches even though dressed stock is about 0.75 by 5.5 inches. DOC PS 20 defines board measure on nominal thickness and width. If you are measuring milled or custom stock with a tape and want the true rectangular volume, enter the measured sizes instead and note that on your cut list.

Can I enter the run in inches instead of feet?

Yes. The industry formula wants length in feet, so if you measured a run in inches, switch the linear feet unit to inches and the tool divides by 12 before applying the formula. Mixed feet and inches such as 8 ft 6 in should be converted to 8.5 ft or 102 in before entry.

Sources

High-trust standards and documented references.

  1. 1. Voluntary Product Standard PS 20-25, American Softwood Lumber Standard

    U.S. Department of Commerce / NIST

    Section 2.2 defines board measure: board feet = nominal thickness (inches) x nominal width (feet) x length (feet).

    https://www.nist.gov/system/files/documents/2024/12/11/PS%2020-25%20Final.pdf

  2. 2. Wood Handbook: Wood as an Engineering Material (FPL-GTR-190), Glossary

    USDA Forest Service, Forest Products Laboratory

    Defines a board foot as a board 12 in long, 12 in wide, and 1 in thick, with practice based on nominal thickness and width and actual length.

    https://www.fpl.fs.usda.gov/documnts/fplgtr/fplgtr190/glossary.pdf

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