Board Foot Calculator

Last Updated Aug 31, 2023

Use the calculator to calculate the number of board feet in a piece of wood or lumber.

What is a Board Foot?

A board foot is a unit of volume, traditionally used for timber, equal to 144 cubic inches (12 inches long by 12 inches wide by 1 inch thick). 

Many lumber yards price hardwood using the board foot as the standard unit of measurement. Unlike softwoods, which are often sold by linear or square feet, hardwoods vary in width and thickness. 

Given that hardwoods are typically more expensive and are chosen for specialized projects like furniture or cabinetry, board feet serve as a standardized pricing metric.

How to Calculate Board Feet

The formula to determine board feet is:

Board Feet = Width (in inches) × Length (in inches) × Thickness (in inches) ÷ 144

Common Lumber Applications and Their Calculations

Here are some common ways that board feet calculations apply in everyday lumber scenarios.

Deck Building

Softwoods, such as cedar or pine, are popular decking materials. When constructing a deck with 2x6 planks, understanding board feet can guide the cost estimation, even if the lumber is priced by linear feet. For instance, a 2x6 plank, which is 1.5 inches thick and 5.5 inches wide, represents 0.763 board feet for every foot of length.

Cabinetry

For crafting elegant cabinets, hardwoods like oak, cherry, or walnut are common choices. If a millwork contractor buys wood that's 3/4 inch in thickness (a typical dimension for cabinet facings) and 8 inches wide, each linear foot of this material equals 0.5 board feet.

Custom Furniture

To craft a dining table using a maple slab that's 2 inches thick and averages 30 inches in width over a 6-foot span, the builder would need 30 board feet of wood.

Here’s the calculation:

30 in × 72 in × 2 in ÷ 144 = 30 board feet

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