Board Foot Calculator – How Much Lumber Do I Need? | CalcLoft
Find out exactly how many board feet of lumber you need.
What is a board foot?
A board foot is a lumber volume unit: 1 ft long × 1 ft wide × 1 in thick (144 cubic inches). Formula:
Board feet = (thickness in × width in × length ft) ÷ 12
Example: a 2×6 that is 8 ft long = (1.5 × 5.5 × 8) ÷ 12 = 5.5 board feet. Note: lumber is priced by nominal size but calculated from actual dimensions.
Board feet quick table
| Board | 8 ft | 10 ft | 12 ft |
|---|---|---|---|
| 2×4 | 5.3 | 6.7 | 8.0 |
| 2×6 | 8.0 | 10.0 | 12.0 |
| 2×8 | 10.7 | 13.3 | 16.0 |
| 2×10 | 13.3 | 16.7 | 20.0 |
Pro tips
- Lumber yards often round up to the nearest board foot
- Add 10% for cuts, warps and mistakes
- Hardwood is sold by the board foot; framing lumber by the piece
Board foot calculator FAQ
How many board feet in a 2x4x8?
A 2×4×8 is about 5.3 board feet (1.5 × 3.5 × 8 ÷ 12).
What's the difference between board foot and linear foot?
A linear foot is just length. A board foot accounts for thickness and width — it measures volume of lumber.
How do I price lumber?
Multiply total board feet by the price per board foot. Hardwoods run $3-15/bf; softwoods $1-3/bf.
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