Board feet in a 2×10×8
There are two honest answers. The wood you actually carry out of the store is 9.25 board feet — a 2×10 really measures 1.5″ × 9.25″. But if you're pricing or trading lumber, the industry counts this board as 13.33 BF, because board feet are by convention figured on the nominal 2″ × 10″ name.
The math, both ways
trade (nominal): 2″ × 10″ × 96″ ÷ 144 = 13.33 BF
Which one do you want? If you're figuring weight, volume, or "how much wood is that really," use 9.25. If you're comparing against hardwood priced per board foot, or reading a mill tally, use 13.33 — 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 2×10 is for
The 2×10 carries floors: around 15–16′ of span at 16″ on center in the strong species, which covers most rooms in most houses. It's also the standard stair-carriage material where the 2×12 won't fit, and — doubled or tripled — the built-up beam under countless decks.
Old-house owners meet the 2×10's ancestors during remodels: joists in pre-1960s homes often measure a true 2″ × 10″ (or close), so sistering a modern 9-1/4″ board against one means shimming. Lumber history shows up as a gap at the subfloor.
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 1.5″ × 9.25″ section, a 8′ board holds 0.77 ft³ of wood — about 27 lb kiln-dried, and closer to 42 lb dripping fresh off the pressure-treated rack.
What that volume costs at hardwood prices
| Price per BF | Actual wood (9.25 BF) | Trade tally (13.33 BF) |
|---|---|---|
| $3.00 | $27.75 | $40.00 |
| $5.00 | $46.25 | $66.67 |
| $7.00 | $64.75 | $93.33 |
| $10.00 | $92.50 | $133.33 |