Board Foot Calculator
Calculate board feet from your lumber dimensions and look up common conversions. A handy tool for working out how much material a reclaimed wood project needs.
Calculate Board Feet
Enter your lumber dimensions below. Board feet are calculated using the nominal dimensions (the name of the board, not the actual planed size).
Formula
Board Feet = (T" x W" x L') / 12
Where T = thickness in inches, W = width in inches, and L = length in feet. This is equivalent to (T x W x L) / 144 when all measurements are in inches.
Calculation Results
2" x 6" x 8'
1152 cu in
Pricing is by quote from partner suppliers in our network.
Linear Feet to Board Feet Conversion
Quick reference for converting linear feet to board feet across common lumber sizes. Board feet are calculated using nominal dimensions.
| Nominal Size | LF per Board Foot | BF per Linear Foot | BF in 8' Board | BF in 10' Board | BF in 12' Board |
|---|---|---|---|---|---|
| 1 x 4 | 3.00 | 0.33 | 2.67 | 3.33 | 4.00 |
| 1 x 6 | 2.00 | 0.50 | 4.00 | 5.00 | 6.00 |
| 1 x 8 | 1.50 | 0.67 | 5.33 | 6.67 | 8.00 |
| 1 x 10 | 1.20 | 0.83 | 6.67 | 8.33 | 10.00 |
| 1 x 12 | 1.00 | 1.00 | 8.00 | 10.00 | 12.00 |
| 2 x 4 | 1.50 | 0.67 | 5.33 | 6.67 | 8.00 |
| 2 x 6 | 1.00 | 1.00 | 8.00 | 10.00 | 12.00 |
| 2 x 8 | 0.75 | 1.33 | 10.67 | 13.33 | 16.00 |
| 2 x 10 | 0.60 | 1.67 | 13.33 | 16.67 | 20.00 |
| 2 x 12 | 0.50 | 2.00 | 16.00 | 20.00 | 24.00 |
| 4 x 4 | 0.75 | 1.33 | 10.67 | 13.33 | 16.00 |
| 6 x 6 | 0.33 | 3.00 | 24.00 | 30.00 | 36.00 |
| 8 x 8 | 0.19 | 5.33 | 42.67 | 53.33 | 64.00 |
How Board Foot Measurement Works
The Board Foot Defined
A board foot (BF) is a unit of volume equal to 144 cubic inches. Picture a board that is 1 inch thick, 12 inches wide, and 12 inches long (1 foot). That is exactly 1 board foot.
Any combination of dimensions that equals 144 cubic inches is also 1 board foot. For example: a 2" x 6" x 12" piece is also 1 board foot (2 x 6 x 12 = 144).
When to Use Board Feet
Board feet are the usual trade unit for hardwood lumber, reclaimed lumber, and specialty woods. They are used when what matters is the volume of wood, not just its length or area.
Softwood framing lumber (2x4s, 2x6s, etc.) is often sold per linear foot or per piece instead. Partner suppliers set their own units and prices, so check whether a quote is per board foot, per linear foot, or per piece.
Nominal vs Actual in Calculations
Board foot calculations in the lumber industry use nominal dimensions, not actual. A 2x6 is counted as a 2" x 6" piece, even though the actual board measures 1.5" x 5.5".
This is important for reclaimed lumber: if you have a full-dimension vintage 2x6 that actually measures 2" x 6", you are getting more wood per nominal board foot than you would with a modern board. Measure the actual size and ask how a supplier counts it.
Calculating for Irregular Pieces
Reclaimed lumber is not always perfectly straight or uniform. For tapered or irregular pieces (like hand-hewn beams), measure the average width and thickness at several points along the length.
For slabs or live-edge boards, measure the width at the narrowest point and the widest point, then average them. Always round to the nearest 1/4 inch for thickness and 1 inch for width.
Board Foot Calculation Examples
| Description | Dimensions | Calculation | Board Feet |
|---|---|---|---|
| Single 2x4, 8 feet long | 2" x 4" x 8' | (2 x 4 x 8) / 12 | 5.33 BF |
| Single 1x6, 10 feet long | 1" x 6" x 10' | (1 x 6 x 10) / 12 | 5.00 BF |
| 6x6 beam, 12 feet long | 6" x 6" x 12' | (6 x 6 x 12) / 12 | 36.00 BF |
| 8x10 beam, 16 feet long | 8" x 10" x 16' | (8 x 10 x 16) / 12 | 106.67 BF |
| 10 pieces of 2x6, 12 feet | 2" x 6" x 12' x 10 | (2 x 6 x 12 x 10) / 12 | 120.00 BF |
| 5/4 decking board, 5.5" x 12' | 1.25" x 5.5" x 12' | (1.25 x 5.5 x 12) / 12 | 6.88 BF |
| Live-edge slab, 2" x avg 18" x 6' | 2" x 18" x 6' | (2 x 18 x 6) / 12 | 18.00 BF |