What Is a Board Foot?
A board foot is a standard unit of measurement in the lumber and woodworking industry that represents the volume of wood. One board foot is equal to a board that is 12 inches long, 12 inches wide, and 1 inch thick — or 144 cubic inches. It’s commonly used to estimate the total amount of wood needed for projects such as framing, flooring, cabinetry, and furniture making.
Understanding board footage is essential when buying lumber, as most suppliers price their products per board foot. Calculating board feet allows you to compare pricing, order the correct quantity, and minimize waste. Whether you're a contractor, carpenter, or DIY woodworker, knowing how to calculate board feet will save you both time and money.
How to Calculate Board Feet
To calculate board feet, use this simple formula:
(Thickness in inches × Width in inches × Length in feet × Quantity) ÷ 12 = Total Board Feet
This formula converts all board dimensions into a volume measurement and divides by 12 to reflect the 12-inch standard used in board foot calculations.
Why Use This Free Board Foot Calculator?
- Quickly estimate lumber volume without manual calculations
- Save time and reduce errors during project planning or purchasing
- Supports bulk calculations with a quantity field for multiple boards
- Ideal for DIYers, carpenters, builders, and project estimators
- Optimized for desktop and mobile use, so you can calculate on-site or in the workshop
Best Practices for Lumber Estimation
- Measure the actual dimensions of each board, especially if using rough-sawn lumber
- Always use the same unit system to avoid conversion errors (inches and feet)
- Include a 10–15% waste factor to account for offcuts, defects, and trimming
- Double-check measurements before placing a lumber order
- Consider the wood species and grain direction if exact yield is important
Common Uses for Board Foot Calculations
- Cabinetry and fine woodworking
- Rough carpentry and framing
- Decking, fencing, and outdoor construction
- Custom furniture and millwork
- Ordering hardwood, softwood, or exotic lumber by volume