Board Feet Calculator
If you’re buying lumber or working on a woodworking project, you’ve likely encountered the term “board feet.” It’s the standard unit used in North America to measure and price hardwood and softwood lumber. Knowing how to calculate board feet is essential for budgeting, ordering the right amount of wood, and avoiding waste.
To make things easier, our Board Feet Calculator provides a fast, accurate way to estimate lumber volume and pricing—perfect for builders, DIYers, carpenters, and contractors alike.
What Is a Board Foot?
A board foot is a unit of measurement for lumber that represents a volume of 1 inch thick × 12 inches wide × 12 inches long (or 144 cubic inches). It accounts for all three dimensions of a board—thickness, width, and length.
Board feet formula:
Board Feet = (Thickness [inches] × Width [inches] × Length [feet]) ÷ 12
Why Use a Board Feet Calculator?
Calculating board feet manually can be time-consuming, especially when you’re working with multiple pieces of varying dimensions. This calculator automates that process so you can:
- ✅ Avoid costly over-ordering
- ✅ Prevent underestimating your materials
- ✅ Quickly estimate cost for budgeting
- ✅ Plan more efficiently for large-scale woodworking or construction projects
How to Use the Board Feet Calculator – Step-by-Step
The tool is simple and requires just four inputs:
- Enter the Thickness (inches):
This is the actual thickness of the board. You can enter fractional values like 0.75 or 1.5. - Enter the Width (inches):
The board’s face width. Standard widths include 4″, 6″, 8″, etc., but the calculator allows any custom value. - Enter the Length (feet):
Input the length of the board in feet, not inches. You can use decimal values (e.g., 6.5 feet). - Enter the Quantity (Number of Pieces):
Specify how many identical boards you’re using. The calculator will multiply the board feet accordingly. - Click “Calculate”:
The tool will display:- Board feet per piece
- Total board feet for all pieces
- Estimated cost (based on $5/board foot by default)
- Click “Reset” to clear the form and start over.
Practical Example: Estimating a Lumber Order
Let’s say you’re building a dining table and need:
- Thickness: 1.5 inches
- Width: 8 inches
- Length: 6 feet
- Quantity: 4 boards
Result:
- Board Feet per Piece: (1.5 × 8 × 6) ÷ 12 = 6 board feet
- Total Board Feet: 6 × 4 = 24 board feet
- Estimated Cost (at $5 per bd.ft): 24 × $5 = $120
With this simple calculation, you now know exactly how much lumber to buy and what it might cost—no guesswork needed.
Common Use Cases for the Board Feet Calculator
This tool is useful in a variety of scenarios:
- 🪚 Woodworkers buying hardwood for furniture or cabinetry
- 🏡 Contractors planning home renovations or custom installations
- 🏗️ Builders sourcing framing lumber
- 🛠️ DIYers estimating project materials
- 🏫 Students or apprentices learning lumber calculations
- 🧾 Suppliers quoting jobs or pricing inventory
Whether you’re buying a single slab or hundreds of feet of lumber, this calculator helps ensure accuracy and efficiency.
15+ Detailed FAQs About Board Feet and Lumber Estimating
1. What is a board foot?
A board foot is a volume measurement of lumber: 1″ thick × 12″ wide × 12″ long or 144 cubic inches.
2. Why is lumber measured in board feet?
It accounts for the thickness, width, and length of a board, giving a more precise volume than linear feet.
3. What’s the formula for board feet?
(Thickness × Width × Length) ÷ 12 – where thickness and width are in inches, and length is in feet.
4. Can I use this calculator for softwood and hardwood?
Yes. The calculation method is the same regardless of wood type.
5. Does this calculator account for waste or cuts?
No. It gives exact volume. Add an extra 10–15% to account for waste, depending on your project.
6. Can I enter dimensions in centimeters or meters?
No. The calculator uses inches and feet. You’ll need to convert metric measurements to imperial.
7. Is thickness always measured in actual inches?
Yes, but be aware that lumber is often sold in nominal sizes. A “2×4″ is actually about 1.5″ × 3.5”.
8. Why divide by 12 in the formula?
To convert the volume in cubic inches to board feet, since one board foot equals 144 cubic inches.
9. Can I calculate total cost using this tool?
Yes. It gives an estimated cost based on a default price per board foot (e.g., $5). You can change this in the script.
10. Is the cost accurate?
The cost is an estimate. Actual pricing varies based on wood type, quality, region, and supplier.
11. Does it work with irregular shapes or live edge boards?
No. It’s designed for rectangular boards. Estimating irregular shapes requires more advanced tools.
12. How do I calculate board feet for a whole lumber list?
Use the calculator for each board size and sum the total board feet.
13. How accurate is this tool?
Very accurate for standard rectangular lumber. It uses the industry-standard board feet formula.
14. Can I use this for plywood or sheet goods?
Not directly. Plywood is usually sold by the sheet (e.g., 4’x8′) and measured in square feet or cubic feet.
15. Can this tool help me quote a client project?
Yes! Combine it with your material markup and labor rates to generate fast, reliable estimates.
16. How much does a board foot weigh?
It depends on wood species. For example, one board foot of oak weighs more than pine.
17. Is the board feet number rounded?
The calculator displays results to two decimal places for accuracy.
18. How do I adjust for pricing changes?
You can modify the script’s price per board foot value (pricePerBoardFoot = 5) to reflect current market prices.
19. Do lumberyards use this formula?
Yes. This is the industry-standard method for pricing dimensional hardwood and softwood lumber.
20. What’s the benefit of using a calculator like this online?
Speed, accuracy, and convenience—especially for large orders or complex projects.
Final Thoughts
Whether you’re a seasoned carpenter or a weekend warrior tackling your next project, this Board Feet Calculator takes the guesswork out of lumber estimating. You’ll know exactly how much wood you need, how much it weighs in board feet, and even what it might cost.
Save time, reduce waste, and work smarter with our free, easy-to-use tool. Try it now and make your next lumber purchase with confidence.