Calculate linear feet for baseboards, convert square feet to linear feet for decking, or measure straight fence runs.
Linear footage (often called "linear feet") is simply a measurement of length in a straight line. Unlike square footage, which measures a 2D area (Length × Width), linear footage only measures one dimension. If you have a board that is 8 feet long, you have exactly 8 linear feet of wood, regardless of how wide or thick the board is.
Calculating linear feet is critical when buying materials that are sold by length rather than area. This includes baseboards, crown molding, trim, fencing, gutters, and weatherstripping.
Home improvement stores sell materials in different ways, which causes massive confusion for DIYers:
When buying composite decking, hardwood flooring, or exterior siding, the store might quote you in "Square Feet," but the actual boards are sold by "Linear Feet." To convert square feet to linear feet, you must know the width of the board.
The Formula: (Total Square Feet × 12) ÷ Board Width (in inches) = Linear Feet
Example: You need to cover 100 square feet of deck using 5.5-inch wide composite boards.
1. Multiply 100 by 12 = 1,200.
2. Divide 1,200 by 5.5 = 218.18 linear feet.
3. Add a 10% waste factor = 240 linear feet of decking needed.
To find the linear footage for trim, you need to calculate the perimeter of the room and subtract the areas where trim isn't needed (like doorways and fireplaces).
The Formula: (Room Length + Room Width) × 2 - (Door Width × Number of Doors) = Linear Feet
A standard 10x10 square room has exactly 40 linear feet of perimeter (10 + 10 + 10 + 10). If the room has one standard 3-foot wide door, you would subtract 3 feet, meaning you need to buy 37 linear feet of baseboard.
Simply measure the total straight-line distance the fence will cover. If your property line is 150 feet long, you have 150 linear feet of fencing. Remember to subtract the width of any gates (e.g., a 6-foot gate means you need 144 linear feet of actual fence panels).
Yes. "Linear feet" is just a term used in construction and retail to clarify that you are measuring in a straight, 1D line, as opposed to "square feet" (2D area) or "cubic feet" (3D volume). One linear foot is exactly 12 inches.
To convert inches to linear feet, simply divide your total inches by 12. For example, if you measure a wall and it is 114 inches long, divide 114 by 12 to get 9.5 linear feet.