Board feet calculator
Convert lumber dimensions to board feet and cubic metres; four 2 × 6 in boards, 8 ft long, make 32 board feet.
- Runs in your browser
- No upload
- Instant result
Quantity estimate only. This does not approve structural safety, load capacity, drainage, fire resistance or building-code compliance. Verify the design and local requirements with a qualified professional. Purchase quantities round up to whole packs.
Assumptions & formula
Formula and assumptions
BF=T(in)W(in)L(ft)n/12; 1BF=0.002359737216m³
The prefilled values are editable examples, not product specifications. Enter your supplier’s yield, density, coverage and packaging values, and add an allowance for overlaps, compaction and cuts where needed.
Purchase counts use the exact entered decimals and unit factors, without a rounding tolerance that could discard a real remainder. π and irrational square roots use enclosing bounds; ambiguous counts produce an error. Counts must be safe integers.
Results
Enter values and press Calculate to see the result here.
How to use this calculator
- Set inputs and units
Enter thickness and width in inches, length in feet and the number of pieces. These fields deliberately use mixed lumber units.
- Calculate
Check this worked example: 1 in×6 in×8 ft /12 =4 board ft per piece; quantity10 →40 board ft ≈0.09438948864 m³
- Results
Board feet measure volume, not linear feet. Multiply the per-piece result by the actual number of pieces.
Questions and limits
Should nominal or finished dimensions be used?
The result follows the dimensions you enter. Use the same nominal or actual convention that the supplier’s pricing is based on.
Which input errors should I correct?
Don't enter meters in the feet field. Dimensions must be positive, and the quantity must be a whole number from 1–100,000.
What does this calculation leave out?
No timber grading, strength, moisture or shrinkage model, price lookup or optimized cutting list.