Board feet in a 1×8×8
There are two honest answers. The wood you actually carry out of the store is 3.63 board feet — a 1×8 really measures 0.75″ × 7.25″. But if you're pricing or trading lumber, the industry counts this board as 5.33 BF, because board feet are by convention figured on the nominal 1″ × 8″ name.
The math, both ways
trade (nominal): 1″ × 8″ × 96″ ÷ 144 = 5.33 BF
Which one do you want? If you're figuring weight, volume, or "how much wood is that really," use 3.63. If you're comparing against hardwood priced per board foot, or reading a mill tally, use 5.33 — the whole trade runs on nominal, for the historical reasons on our nominal vs actual page. (Construction lumber itself is usually priced per piece, so at the store neither number appears on the shelf tag.)
What a 1×8 is for
The 1×8 is the classic board-and-batten siding field board, the barn-siding size, and a favorite bookshelf depth for paperbacks. At 7-1/4″ actual, two of them edge-glued make a 14-1/2″ panel — the traditional route to cabin shelving and bench seats.
Wider boards mean wider seasonal movement: a pine 1×8 can change width by an eighth of an inch between summer and winter. Board-and-batten exists precisely to let each board move behind a batten that hides the shifting gap.
Eight feet is the default length — it matches the ceiling, fits inside a pickup bed with the tailgate down, and wastes the least when cut for typical walls. It's usually the cheapest per foot, too, because it's the volume seller.
Heft check: at its true 0.75″ × 7.25″ section, a 8′ board holds 0.30 ft³ of wood — about 11 lb kiln-dried, and closer to 17 lb dripping fresh off the pressure-treated rack.
What that volume costs at hardwood prices
| Price per BF | Actual wood (3.63 BF) | Trade tally (5.33 BF) |
|---|---|---|
| $3.00 | $10.88 | $16.00 |
| $5.00 | $18.13 | $26.67 |
| $7.00 | $25.38 | $37.33 |
| $10.00 | $36.25 | $53.33 |