Use our board foot calculator to quickly and accurately estimate the amount of usable lumber in a log or piece of timber, and number of boards you need.
- For 1-inch thick boards: 1 board foot = 1 square foot
- For 3/4-inch thick boards: 1 board foot = 1.33 square feet
- For 1/2-inch thick boards: 1 board foot = 2 square feet
Board Foot Calculator
- Board feet in a 2x4x10 = Board Feet = (1.5 * 3.5 * 10) / 12 = 4.375 board feet
- Board feet in 2x2x12 = Board Feet = (1.5 * 1.5 * 12) / 12 = 2.25 board feet
- Board Feet in a 2x6x12 = Board Feet = (1.5 * 5.5 * 12) / 12 = 8.25 board feet
- Board Feet in a 2x6x10 = Board Feet = (1.5 * 5.5 * 10) / 12 = 6.875 board feet
| Thickness (in) | Width (in) | Length (ft) | Board Feet |
|---|---|---|---|
| 1 | 6 | 8 | 4 |
| 1 | 8 | 10 | 5.33 |
| 1 | 12 | 6 | 6 |
| 1.5 | 3.5 | 12 | 5.25 |
| 1.5 | 4 | 10 | 5 |
| 1.5 | 6 | 8 | 6 |
| 2 | 4 | 10 | 6.67 |
| 2 | 6 | 12 | 12 |
| 2 | 8 | 16 | 21.33 |
| 2 | 10 | 10 | 12.5 |
| 2 | 12 | 14 | 28 |
| 2.5 | 4 | 10 | 8.33 |
| 2.5 | 6 | 12 | 15 |
| 3 | 4 | 8 | 8 |
| 3 | 6 | 10 | 15 |
| 3 | 8 | 12 | 24 |
| 3 | 10 | 14 | 35 |
| 4 | 4 | 10 | 13.33 |
| 4 | 6 | 12 | 24 |
| 4 | 8 | 16 | 42.67 |
Board Foot Formula
The formula for calculating board feet is straightforward:
Board Feet = (Thickness in inches * Width in inches * Length in feet) / 12- One board foot equals 1 inch thick by 12 inches wide by 1 foot long (1″ x 12″ x 1′).
- The formula assumes the board is at least 1 inch thick.
- For logs, a modified version is often used: (D x D x L) / 16
Where D is the diameter in inches and L is the length in feet.
Different scaling rules (Doyle, Scribner, International 1/4 Inch) may use variations of this formula to account for factors like log taper and saw kerf.
How to Calculate Board Feet
To calculate board feet, follow these steps:
Measure Dimensions:
- Thickness in inches
- Width in inches
- Length in feet
Apply the Formula: Board Feet = (Thickness x Width x Length) / 12
For Logs, Use: Board Feet = (Diameter x Diameter x Length) / 16
Example for Lumber:
- 2″ thick, 6″ wide, 8′ long board
- (2 x 6 x 8) / 12 = 8 board feet
Example for a Log:
- 16″ diameter, 12′ long log
- (16 x 16 x 12) / 16 = 192 board feet
For a board measuring 1 inch thick, 8 inches wide, and 10 feet long:
Board Feet = (1 * 8 * 10) / 12 = 6.67 board feetHow to Convert board feet to square feet?
- A board foot is a volume measurement (1 ft x 1 ft x 1 inch)
- A square foot is an area measurement (1 ft x 1 ft)
Square Feet = Board Feet / (Thickness in inches / 12)Convert 100 board feet of 1-inch thick lumber to square feet.
Square Feet = 100 / (1 / 12) = 1200 square feetHow many square feet are in 200 board feet?
200 board feet = 200 × (1/12) cubic feet = 16.67 cubic feetIf we spread out 16.67 cubic feet of lumber at 0.75 inches (0.0625 feet) thick, we can calculate the square footage:
Square feet = Volume in cubic feet ÷ Thickness in feet
Square feet = 16.67 ÷ 0.0625 = 266.67 square feet
A 200 board feet is equivalent to approximately 266.67 square feet of 1-inch (nominal) lumber.
References
- American Hardwood Export Council – Lumber Measurement
- Forest Products Laboratory – Wood Handbook
- National Institute of Standards and Technology – Wood: Lumber
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