Inputs to result
Board feet per piece = thickness (in) × width (in) × length (ft) ÷ 12; total = per-piece board feet × quantity.
Carpentry & Framing
Board Foot Calculator
Calculate total and per-piece board feet from nominal or actual lumber thickness, width, length, and piece count for US timber estimates.
Enter actual or nominal lumber dimensions consistently. The calculator returns total board feet and volume per piece.
Calculation and worked example reviewed 2026-11-12. See our calculation methodology.
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Carpentry & Framing
US UNITSEnter your measurements
YOUR ESTIMATE
133.33 board feet13.33 per board10 boards × 2 in × 8 in × 10 ft.
Uses the entered dimension basis; confirm nominal versus actual with the supplier.
Formula and example
How this calculation works
This estimator converts your entered jobsite inputs (board thickness, board width, board length, number of boards) into consistent US trade units, computes the exact geometric baseline first, and then applies any selected waste or order allowance so you can verify both numbers before purchasing materials.
How does the board foot calculator formula work?
Board feet per piece = thickness (in) × width (in) × length (ft) ÷ 12; total = per-piece board feet × quantity.
(Board Foot Calculator)where:
- Board thickness – Entered in in (default reference: 2 in);
- Board width – Entered in in (default reference: 8 in);
- Board length – Entered in ft (default reference: 10 ft);
- Number of boards – Entered in boards (default reference: 10 boards);
Check the math
Ten boards measuring 2 in × 8 in × 10 ft contain 2 × 8 × 10 ÷ 12 × 10 = 133.33 board feet using nominal dimensions.
Quick lookup chart
Standard Nominal Lumber Board-Foot Reference Table
1 board foot = 144 cu in (1 in × 12 in × 12 in), calculated from nominal dimensions.
| Nominal Size | 8 ft Board | 10 ft Board | 12 ft Board |
|---|---|---|---|
| 1 × 6 | 4.00 BF | 5.00 BF | 6.00 BF |
| 2 × 4 | 5.33 BF | 6.67 BF | 8.00 BF |
| 2 × 6 | 8.00 BF | 10.00 BF | 12.00 BF |
| 2 × 8 | 10.67 BF | 13.33 BF | 16.00 BF |
| 2 × 10 | 13.33 BF | 16.67 BF | 20.00 BF |
Before you use this result
Board feet are a volume unit. Lumber is often sold by nominal dimensions even when actual dressed dimensions are smaller. Confirm the supplier's pricing basis and allowance for cuts or defects.
- Softwood framing and hardwood rough stock are priced using nominal thickness and width (e.g., 2 × 8, 4/4, 8/4), not dressed S4S dimensions.
- For rough hardwood quoted in quarters (4/4 = 1 in, 5/4 = 1.25 in, 6/4 = 1.5 in, 8/4 = 2 in), enter the decimal inch equivalent in the thickness field.
- Add 10% to 20% extra board footage for crosscut kerfs, rip waste, knots, and grain matching on cabinet or millwork projects.
Questions answered
Calculator FAQ
What is one board foot?+
One board foot is 144 cubic inches, equivalent to a 1 in × 12 in × 12 in volume.
How do I calculate board feet for lumber pricing?+
Multiply thickness in inches × width in inches × length in feet, then divide by 12. For example, a 2x8 board that is 10 feet long is (2 × 8 × 10) ÷ 12 = 13.33 board feet. Multiply total board feet by price per board foot.
Should I use nominal or actual size?+
Use the same dimension basis the supplier uses for pricing; do not mix nominal and actual dimensions.