How this board foot calculator works
A board foot is lumber's volume unit — 144 cubic inches of nominal wood. One formula, no exceptions:
Worked example: board feet in a stack of 4/4 stock
Ten 4/4 × 6 in × 8 ft boards: each is 1 × 6 × 8 ÷ 12 = 4 board feet, so the stack is 40 BF — $200 at $5 per board foot. Hardwood dealers will tally it exactly this way at the rack.
Board feet in common lumber sizes
| Nominal size | Board feet |
|---|---|
| 1 × 6 | 4 |
| 1 × 8 | 5.33 |
| 2 × 4 | 5.33 |
| 2 × 6 | 8 |
| 2 × 8 | 10.67 |
| 2 × 10 | 13.33 |
| 2 × 12 | 16 |
Nominal sizes, quarters, and MBF pricing
- Nominal vs actual: surfacing shrinks a 2×4 to 1½ × 3½ — but board feet always count the nominal 2 × 4. Budget projects on actual, buy on nominal.
- Quarters: hardwood thickness is called in quarter inches — 4/4 ("four-quarter") is 1 in, 5/4 is 1¼, 8/4 is 2. The chips above set them directly.
- MBF: mills and wholesalers quote per thousand board feet; $800/MBF is $0.80/BF. The substrip converts your tally.
Board foot FAQ
What is a board foot?
A volume unit for lumber: 144 cubic inches, the size of a 1 in × 12 in × 12 in piece — figured on nominal (rough-sawn) dimensions. Board feet = thickness (in) × width (in) × length (ft) ÷ 12.
How many board feet are in a 2×4×8?
5.33 board feet: 2 × 4 × 8 ÷ 12. A 2×6×8 is 8 BF, a 2×10×8 is 13.33, and a 2×12×8 is 16 — the table on this page lists the common sizes.
Why do board feet use nominal sizes when the wood is smaller?
Because the measure describes the rough-sawn board the mill started from, before surfacing takes it to 1½ × 3½. Hardwood dealers price the same way in "quarters" — 4/4 is 1 in nominal, 8/4 is 2 in — so nominal-in, nominal-out is the trade convention everywhere.
What is the difference between a board foot and a linear foot?
A linear foot is just length along the board, ignoring section; a board foot is volume. Dimensional framing lumber usually prices per piece or per linear foot, while hardwoods and rough stock price per board foot — this calculator converts your tally for the latter.
How much does a board foot of lumber cost?
In 2026, roughly $3–6 per board foot for common domestic hardwoods like oak, maple and ash, $6–12 for walnut and cherry, and more for figured or exotic stock. Type your quote into the price field — dealers also quote per MBF (thousand board feet) for volume.
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