Board Foot Calculator
Calculate board feet for lumber volume and pricing
How to Use
- Enter lumber dimensions (thickness, width, length)
- Specify quantity of pieces
- Optionally enter price per board foot for cost calculation
- Choose your preferred unit system (imperial or metric)
- Click calculate to get volume and cost estimates
What is a Board Foot?
A board foot is a unit of volume measurement used in the lumber industry. It represents the volume of a piece of wood that is 1 foot long, 1 foot wide, and 1 inch thick (12" × 12" × 1" = 144 cubic inches).
Board feet are commonly used to price and sell lumber, especially hardwoods and specialty woods where precise volume measurement is important.
Board Foot Formula
Formula:
board feet = thickness (in) × width (in) × length (ft) ÷ 12
board feet = thickness (m) × width (m) × length (m) ÷ 0.002359737216
- Imperial: thickness and width in inches, length in feet; divide by 12.
- Metric: all three dimensions in meters; divide cubic meters by 0.002359737216.
- 1 board foot = 144 cubic inches = 0.002359737216 cubic meters. Multiply by the number of pieces.
Common Lumber Sizes
| Nominal Size | Actual Size | Board Feet per 8' Length |
|---|---|---|
| 1×4 | 0.75" × 3.5" | 1.75 |
| 1×6 | 0.75" × 5.5" | 2.75 |
| 1×8 | 0.75" × 7.25" | 3.63 |
| 1×10 | 0.75" × 9.25" | 4.63 |
| 1×12 | 0.75" × 11.25" | 5.63 |
| 2×4 | 1.5" × 3.5" | 3.50 |
| 2×6 | 1.5" × 5.5" | 5.50 |
| 2×8 | 1.5" × 7.25" | 7.25 |
| 2×10 | 1.5" × 9.25" | 9.25 |
| 2×12 | 1.5" × 11.25" | 11.25 |
Lumber Pricing
Lumber may be quoted per board foot. Use the supplier’s actual price for the selected species and grade; no average species prices are assumed.
- Softwoods (pine, fir): Ask for a current quote per board foot.
- Hardwoods (oak, maple): Ask for a current quote per board foot.
- Exotic woods (teak, mahogany): Ask for a current quote per board foot.
- Reclaimed lumber: Ask for a current quote per board foot.
Enter your supplier’s current price per board foot if you want a cost. Lumber species, grade, moisture, dimensions, quantity, and delivery can affect a quote; no price is built in.
Lumber Buying Tips
- Always calculate board feet before purchasing to compare prices
- Consider waste factor (typically 10-20%) for cuts and defects
- Check moisture content - kiln-dried is preferred for indoor projects
- Inspect for knots, warping, and other defects
- Buy slightly more than needed to account for mistakes
- Consider the grade of lumber for your project needs
- Ask about delivery and handling fees
Frequently Asked Questions
- How accurate is this board foot calculator?
- This calculator uses entered actual dimensions and rounds board feet to 2 decimal places. Supplier billing conventions can differ; confirm their measurements and method.
- What's the difference between nominal and actual lumber sizes?
- Nominal size names lumber, such as 2×4. Actual dimensions after milling may be 1.5" × 3.5". Enter actual dimensions; nominal sizes are not converted.
- Why is lumber priced per board foot?
- Board foot pricing allows for fair comparison between different sizes and species of lumber. It accounts for the actual volume of wood you're purchasing, making it easier to compare costs across different dimensions and species.
- How do I account for waste when buying lumber?
- Add 10-20% to your calculated board feet to account for waste from cuts, defects, and mistakes. For complex projects or beginners, consider adding even more. It's better to have extra lumber than to run short mid-project.
- Can I use this calculator for metric lumber?
- Enter all three dimensions in meters. Divide their product in cubic meters by 0.002359737216 to get board feet. For example, 0.05 × 0.1 × 3 m = 0.015 m³ = 6.36 board feet; 1 m³ = 423.78 board feet.
- How do I calculate one 2×4 that is 8 feet long?
- With actual dimensions of 1.5 inches by 3.5 inches: 1.5 × 3.5 × 8 ÷ 12 = 3.50 board feet. A supplier may use a different pricing convention.