How to calculate board feet
board feet = thickness (in) × width (in) × length (ft) × pieces ÷ 12price = board feet × price per board footThe result uses the actual dimensions and quantity entered; it does not add a project waste factor.
Board foot calculator
Measure a board, calculate its board-foot volume, and see its price at the seller's rate per board foot.
Enter the board dimensions
Use the dimensions used by the seller. For rough lumber, those may differ from the final surfaced size.
Use the seller's tally method
Hardwood dealers and sawmills may tally rough dimensions, use nominal thickness such as 4/4 or 8/4, round widths or lengths, or set minimum charges. Confirm grading, moisture, milling, and tally rules before purchasing.
Worked examples
Nominal size and actual size give different answers
Rough 4/4 board1 in × 6 in × 8 ft ÷ 12 = 4.00 board feet
Surfaced boardA board measured at 13/16 in × 5.5 in × 8 ft is 2.98 board feet.
Construction 2×4Using its actual 1.5 in × 3.5 in size, an 8 ft board is 3.50 board feet.
Ten boardsTen actual 1.5 in × 3.5 in × 8 ft boards total 35.00 board feet.
Quarter-based rough thickness notation
| Lumber name | Nominal rough thickness | Decimal inches |
|---|---|---|
| 4/4 | 1 inch | 1.00 |
| 5/4 | 1¼ inches | 1.25 |
| 6/4 | 1½ inches | 1.50 |
| 8/4 | 2 inches | 2.00 |
These are trade thickness names, not guaranteed finished measurements. Surfacing and a dealer's tally rules can change the billed dimensions.