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How Is Hardwood Lumber Sold?

Commercial hardwood is sold by the board foot, with thickness named in quarters — e.g. 4/4, 6/4, 8/4, etc. Board feet = thickness × width × length (all in inches) ÷ 144, using nominal rough thickness even after a board is surfaced. At Fells Hardwood Supply in Hutto we sell lumber in standard board-foot pricing. Widths and lengths vary from board to board, and if you need specific sizes we can mill boards for you at a fair rate.

Board feet (the pricing unit)

BF = Thickness (in) × Width (in) × Length (in) ÷ 144

One board foot is 144 cubic inches — think of a piece 1" thick × 12" wide × 12" long. A board that measures 1" × 6" × 96" is (1 × 6 × 96) ÷ 144 = 4 board feet. Add up the boards you pull, then add a waste buffer before you settle the ticket. That’s the same math every commercial dealer uses.

One board foot equals 144 cubic inches: 1 by 12 by 12 inches 1 board foot = 144 in³ 1" 12" 12" Example board 1" × 6" × 96" = 4 BF (1 × 6 × 96) ÷ 144 = 4 Use nominal rough thickness in the formula
Board feet measure volume. Dealers tally T × W × L in inches, then divide by 144 — same math whether the board is rough or already surfaced.

Thickness in quarters (4/4, 6/4, 8/4, etc.)

Quarters name rough thickness. 4/4 is about 1" rough and typically finishes near 13/16" or 3/4" after jointing and planing — it is not a finished 1" board. 5/4 is about 1¼" rough, 6/4 about 1½", 8/4 about 2" — and thicker stock (10/4, 12/4, 16/4, and more) shows up by species and pack. Buy starting thickness for the finished size you need after milling, not the finished size itself.

4/4, 6/4, and 8/4 rough thickness examples with finished size after milling 4/4 ~1" rough ~¾"–13/16" after milling 6/4 ~1½" rough thinner after mill buy starting size 8/4 ~2" rough thinner after mill etc. also stock
Quarters name rough thickness (examples: 4/4, 6/4, 8/4, and thicker packs by species). Finished size is always less after jointing and planing.

Why does S2S still use 1" in the math for 4/4?

Surfacing removes wood that was part of the original blank. Dealers price nominal rough thickness so everyone tallies the same way — you’re paying for the wood it took to make that blank, including what came off on the mill floor. If two stores quoted different thickness numbers for the same physical board, you couldn’t compare prices.

What's the difference between board foot and linear foot?

Board foot is volume. Linear foot is length of a piece with a fixed width and thickness — common for moulding and pre-sized boards. Hardwood dealers quote board feet. Don’t convert “I need eight feet of 1×6” thinking into dealer pricing without doing the volume math; the units describe different products.

Board foot is volume; linear foot is length of a fixed-section piece Board foot volume (T × W × L) dealer hardwood pricing Linear foot length only (fixed section) moulding / stick sizes
Do not translate “eight feet of 1×6” into a dealer ticket without converting to board feet.

Will my 4/4 always finish at 3/4"?

Often, if the blank is reasonably straight and you don’t have to chase a bad cup or twist. Skip planing, warp, or a thin start can leave you thinner. Choose boards — and starting thickness — with your finished target in mind. When in doubt, step up a quarter.

Deeper teaching: How board feet work · Thickness and milling. Related FAQs: Rough / S2S / S3S / S4S · S4S or S2S? · How much wood do I need? · All FAQs

Fells Hardwood Supply — Hutto, TX — serving Austin, Round Rock, Cedar Park, Georgetown, and the greater Austin metro.