Board Foot Calculator
Calculate board feet for lumber purchasing and cost estimation. Enter the thickness, width, and length to get the total board feet and estimated cost.
Single Board Calculation
Cost Estimator
Common Lumber Sizes Reference
Standard dimensional lumber sizes with board foot calculations for 8-foot and 12-foot lengths.
| Nominal Size | Actual Size | Board Feet (8 ft) | Board Feet (12 ft) |
|---|---|---|---|
| 1x2 | 0.75" × 1.5" | 0.11 | 0.17 |
| 1x4 | 0.75" × 3.5" | 0.22 | 0.33 |
| 1x6 | 0.75" × 5.5" | 0.33 | 0.50 |
| 1x8 | 0.75" × 7.25" | 0.44 | 0.67 |
| 2x4 | 1.5" × 3.5" | 0.44 | 0.67 |
| 2x6 | 1.5" × 5.5" | 0.67 | 1.00 |
| 2x8 | 1.5" × 7.25" | 0.89 | 1.33 |
| 2x10 | 1.5" × 9.25" | 1.11 | 1.67 |
| 2x12 | 1.5" × 11.25" | 1.33 | 2.00 |
| 4x4 | 3.5" × 3.5" | 0.78 | 1.17 |
| 4x6 | 3.5" × 5.5" | 1.33 | 2.00 |
| 6x6 | 5.5" × 5.5" | 2.00 | 3.00 |
How to Calculate Board Feet
The Board Foot Formula:
Board Feet = (Thickness × Width × Length) ÷ 144
Where thickness and width are in inches, length is in feet, and 144 is the number of cubic inches in a board foot.
A board foot is a volume measurement for lumber equal to one square foot of material that is one inch thick (144 cubic inches). This standardized unit allows lumber dealers and woodworkers to price and estimate wood across different dimensions and species.
Important: Always use the nominal dimensions (the name of the lumber like "2x4") rather than actual dimensions when calculating board feet, as lumber is sold and priced based on nominal sizes. A "2x4" actually measures 1.5" × 3.5" but is still calculated as 2" × 4" for board foot pricing.
Worked Examples
Example 1: Standard 2x4
Dimensions: 2" × 4" × 8 ft
Calculation: (2 × 4 × 8) ÷ 144 = 64 ÷ 144 = 0.44 board feet
For 20 boards: 0.44 × 20 = 8.89 board feet
At $1.50/bf: 8.89 × $1.50 = $13.33
Example 2: Deck Board
Dimensions: 2" × 6" × 12 ft
Calculation: (2 × 6 × 12) ÷ 144 = 144 ÷ 144 = 1.00 board foot
For 50 boards: 1.00 × 50 = 50 board feet
At $2.00/bf: 50 × $2.00 = $100.00
Example 3: Hardwood Plank
Dimensions: 1" × 8" × 10 ft
Calculation: (1 × 8 × 10) ÷ 144 = 80 ÷ 144 = 0.56 board feet
For 15 boards: 0.56 × 15 = 8.33 board feet
At $5.00/bf: 8.33 × $5.00 = $41.67
Example 4: Post Material
Dimensions: 4" × 4" × 8 ft
Calculation: (4 × 4 × 8) ÷ 144 = 128 ÷ 144 = 0.89 board feet
For 12 posts: 0.89 × 12 = 10.67 board feet
At $1.75/bf: 10.67 × $1.75 = $18.67
Lumber Pricing Guide
Typical price ranges per board foot as of 2024. Prices vary by region, grade, and market conditions.
| Wood Type | Species Examples | Price Range (per bf) |
|---|---|---|
| Construction Softwood | Pine, Fir, Spruce | $0.50 - $2.00 |
| Premium Softwood | Cedar, Redwood | $2.00 - $4.00 |
| Domestic Hardwood | Oak, Maple, Cherry | $3.00 - $8.00 |
| Premium Hardwood | Walnut, Mahogany | $8.00 - $15.00 |
| Exotic Hardwood | Teak, Ebony, Purpleheart | $15.00 - $30.00+ |
Frequently Asked Questions
What is a board foot and how do I calculate it?
How do I calculate board feet for multiple boards?
Why is lumber pricing done by board foot?
What is the difference between nominal and actual lumber dimensions?
How much does lumber cost per board foot?
Can I use this calculator for hardwood and softwood?
Privacy & Limitations
All calculations are performed locally in your browser. No data is sent to our servers. This calculator uses standard board foot formulas for lumber volume. Prices shown are estimates only and vary by location, supplier, market conditions, wood species, and grade. Always verify pricing with your local lumber dealer before making purchases. For structural applications, consult with a professional and follow local building codes.
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Board Foot Calculator FAQ
What is a board foot and how do I calculate it?
A board foot is a unit of lumber volume equal to 144 cubic inches (12 inches × 12 inches × 1 inch). The formula is (Thickness in inches × Width in inches × Length in feet) ÷ 144. For example, a 2×4×8 board is (2 × 4 × 8) ÷ 144 = 0.44 board feet.
How do I calculate board feet for multiple boards?
Calculate board feet for one board using the formula, then multiply by the number of boards. For example, ten 2×6×10 boards equals (2 × 6 × 10) ÷ 144 = 0.83 board feet per board × 10 boards = 8.33 total board feet.
Why is lumber pricing done by board foot?
Board foot pricing standardizes lumber costs across different sizes and species. Instead of pricing each dimension separately, lumber dealers charge per board foot, making it easy to compare costs and estimate project budgets regardless of board size.
What is the difference between nominal and actual lumber dimensions?
Nominal dimensions are the names we use (2×4, 2×6) while actual dimensions are smaller due to planing. A nominal 2×4 measures 1.5 inches × 3.5 inches. For board foot calculations, always use nominal dimensions as lumber is sold and priced by nominal size.
How much does lumber cost per board foot?
Lumber prices vary by species, grade, and market conditions. As of 2024, construction-grade softwood typically ranges from $0.50 to $2.00 per board foot, hardwoods from $3 to $15+ per board foot, and premium exotic woods can exceed $20 per board foot.
Can I use this calculator for hardwood and softwood?
Yes, the board foot formula works for all lumber types including softwood (pine, fir, cedar), hardwood (oak, maple, walnut), and exotic species. The calculation is the same; only the price per board foot differs based on wood type and grade.