FreeBoard Foot Calculator
This online board foot calculator adds up a whole lumber order. Add each board with its thickness, width and length: the calculator gives the board feet of each one, the total with a waste allowance, the cubic metres and the cost at your lumber yard’s price.
Your boards
| Qty | Thickness (in) | Width (in) | Length (ft) | Board ft | Remove |
|---|---|---|---|---|---|
| 16 | |||||
| 8 |
Type thickness in quarters (4/4, 8/4) or fractions. Dimension lumber is counted at its nominal size: a 2×4 is 2 × 4 in.
- Board feet
- 24
- With 15% waste
- 27.6
- Cubic metres
- 0.065
- Linear feet
- 44
The formula
board feet = thickness (in) × width (in) × length (ft) ÷ 12
First row: 4 × 1 × 6 × 8 ÷ 12 = 16 board feet
- Enter the quantity, thickness, width and length of each board.
- Set a waste allowance and, if you like, the price per board foot.
- Read the total board feet, cubic metres and cost.
Board feet of common lumber
Counted at the nominal size (thickness × width in inches × length in feet ÷ 12):
| Board | Board feet | Board | Board feet |
|---|---|---|---|
| 1×4×8 | 2.67 | 2×6×8 | 8 |
| 1×6×8 | 4 | 2×6×12 | 12 |
| 1×8×8 | 5.33 | 2×8×8 | 10.67 |
| 1×12×8 | 8 | 2×10×12 | 20 |
| 2×4×8 | 5.33 | 2×12×16 | 32 |
| 2×4×10 | 6.67 | 4×4×8 | 10.67 |
How to calculate board feet
A board foot is a piece of wood 1 in thick, 12 in wide and 12 in long: 144 cubic inches. Multiply the thickness by the width in inches and the length in feet, then divide by 12. A board 1 in thick, 6 in wide and 8 ft long is 1 × 6 × 8 ÷ 12 = 4 board feet.
With all three sizes in inches, divide by 144 instead. In metric, one board foot is 2.36 litres (0.00236 m³), so a cubic metre is about 424 board feet.
Rough lumber and dimension lumber
Hardwood is sold rough, by its thickness in quarters of an inch: 4/4 is 1 in, 5/4 is 1 1/4 in, 8/4 is 2 in. Board feet are counted at that rough thickness, before planing. Softwood dimension lumber is counted at its nominal size: a 2×4 is really 1 1/2 × 3 1/2 in, but 2 × 4 in for the board feet, so a 2×4×8 is 5.33 board feet.
How much extra to buy
Rough boards have splits, knots and sapwood, and planing a 4/4 board flat usually leaves it 13/16 in thick. Add 15–20% for clear, straight lumber and 30% or more for lower grades, or when the colour and grain of the parts must match.
Board feet, linear feet and square feet
Linear feet measure only the length, whatever the width of the board. Square feet measure an area, for sheet goods and flooring. Board feet measure a volume, which is why hardwood is priced by the board foot and plywood by the sheet.
Start from a furniture plan instead
All plans →Do not want to work out every part? Pick a design, type its size and get the cut list.
Frequently asked questions
What does MBF mean in lumber?
A thousand board feet (M is the Roman numeral for 1,000). Lumber yards quote framing lumber per MBF: $650 per MBF is $0.65 per board foot.
How many board feet are in a 2x4x8?
2 × 4 × 8 ÷ 12 = 5.33 board feet, counted at the nominal size.
How many board feet are in a cubic metre?
About 424. One board foot is 0.00236 m³ (2.36 litres).
Are board feet measured before or after planing?
Before. Rough hardwood is counted at its rough thickness in quarters, and surfaced boards are usually still sold at the board feet of their rough size.
How do I convert linear feet to board feet?
Multiply the linear feet by the thickness and the width in inches, then divide by 12. Ten linear feet of 1 × 6 is 10 × 1 × 6 ÷ 12 = 5 board feet.