Board Foot Calculator
Enter the board size and how many you need. You get board feet, linear feet and cubic feet, plus the cost if you know the price per board foot.
- Nominal or actual sizes
- Hardwood and softwood
- Cost per board foot
2 Results
Updates as you type| Board feet per piece | 10 |
|---|---|
| Total board feet | 120 |
| Cubic feet | 10 |
| Cubic metres | 0.2832 |
Quick answer
Board feet = thickness (in) × width (in) × length (ft) ÷ 12. A 2×6 that's 10 ft long is 2 × 6 × 10 ÷ 12 = 10 board feet, so 12 of them are 120 board feet. A 2×4×8 is 5⅓ board feet.
Board feet for common lumber
| Lumber | 8 ft | 10 ft | 12 ft | 16 ft |
|---|---|---|---|---|
| 1×4 | 2.67 | 3.33 | 4.00 | 5.33 |
| 1×6 | 4.00 | 5.00 | 6.00 | 8.00 |
| 1×8 | 5.33 | 6.67 | 8.00 | 10.67 |
| 2×4 | 5.33 | 6.67 | 8.00 | 10.67 |
| 2×6 | 8.00 | 10.00 | 12.00 | 16.00 |
| 2×8 | 10.67 | 13.33 | 16.00 | 21.33 |
| 2×10 | 13.33 | 16.67 | 20.00 | 26.67 |
| 2×12 | 16.00 | 20.00 | 24.00 | 32.00 |
| 4×4 | 10.67 | 13.33 | 16.00 | 21.33 |
| 6×6 | 24.00 | 30.00 | 36.00 | 48.00 |
Nominal sizes, one piece each. Use the calculator above for your exact size.
What a board foot is
A board foot is a volume: a piece of wood 1 inch thick, 12 inches wide and 12 inches long, or 144 cubic inches. Lumberyards price hardwood and many softwoods by the board foot, so it's how you compare a stack of boards with a single beam.
The formula is thickness (in) × width (in) × length (ft) ÷ 12. If you measure the length in inches instead, divide by 144.
Worked example: 12 boards of 2×6×10
- One board: 2 × 6 × 10 ÷ 12 = 10 board feet
- Twelve boards: 120 board feet, or 120 linear feet
- At $1.50 per board foot, that's $180.00
Nominal vs. actual size
Softwood dimension lumber is named and tallied by its nominal size. A 2×4 actually measures 1½" × 3½" after drying and planing, but it still counts as 2" × 4" for board feet. Hardwood is sold rough by thickness in quarters of an inch: 4/4 ("four quarter") is 1" thick, 5/4 is 1¼", 8/4 is 2". Use those nominal thicknesses in the calculator unless your supplier says they tally on the surfaced size.
| Hardwood thickness | Inches |
|---|---|
| 4/4 | 1 |
| 5/4 | 1¼ |
| 6/4 | 1½ |
| 8/4 | 2 |
| 12/4 | 3 |
Board feet vs. linear feet
Linear feet is just length, ignoring thickness and width. Trim, decking and fencing are often priced per linear foot. To compare a per-board price with a board-foot price, enter the price per board above and the calculator converts it.
Buying random-width hardwood? Order about 20–30% more board feet than your cut list needs to allow for defects and offcuts. That's a common woodworking rule of thumb, not a standard, so check with your lumberyard.
Frequently asked questions
How many board feet are in a 2×4×8?
A 2×4 that is 8 ft long is 2 × 4 × 8 ÷ 12 = 5.33 board feet, using its nominal size.
How do I calculate board feet in a log?
Logs are estimated with log rules (Doyle, Scribner or International ¼-inch), which allow for saw kerf and slabs. This calculator is for sawn lumber.
Is a board foot the same as a square foot?
No. A square foot is an area. A board foot is a volume: one square foot of board 1 inch thick. A 2-inch-thick board has 2 board feet per square foot.
Last reviewed 2026-10-23. See how we calculate for our sources and assumptions.