What Is a Linear Foot?

Linear Foot Definition

A linear foot (LF) is simply 12 inches of length. The word "linear" emphasizes that you are measuring in a straight line — as opposed to area (square feet) or volume (cubic feet). Think of a linear foot as the distance a tape measure reads when stretched in a straight line.

For example, a standard 2x4 piece of lumber that is 8 feet long is 8 linear feet — regardless of it being 2 inches thick and 4 inches wide.

Linear Foot vs Square Foot

The key difference: Linear feet ignores width, square feet requires it. A 10-foot-long board that is 1 foot wide covers 10 square feet. A 10-foot-long board that is 6 inches wide covers only 5 square feet — but both are 10 linear feet.

Linear Foot vs Board Foot

A board foot (BF) is a unit of wood volume equal to 144 cubic inches — a piece of wood 12 inches long, 12 inches wide, and 1 inch thick. Board feet accounts for length, width, and thickness, while linear feet only accounts for length.

Common Uses of Linear Feet

According to the National Association of Home Builders (NAHB), the average single-family home in the United States contains approximately 350 linear feet of baseboard trim, 180 linear feet of kitchen cabinetry, and 200–250 linear feet of exterior fence line. Linear feet is the pricing unit for all of these materials because each is installed as a continuous run rather than covering a surface area.

• Fencing: Sold and installed by the linear foot
• Baseboards and Trim: Priced per linear foot
• Flooring planks: Sold individually but calculated in linear feet for installation
• Gutters: Seamless gutters are measured and priced by linear foot
• Countertops: Stone and laminate countertops priced per linear foot
• Cabinets: Kitchen cabinets priced by linear foot of cabinet run
• Freight shipping: LTL carriers charge by linear feet of trailer space
• Pipe and conduit: Plumbers and electricians buy pipe by the linear foot