Quick answer: Linear footage is the total length of material in feet. For area-based needs, divide the total square footage by the material's width in feet to get linear feet.
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 Γ 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 Γ 12) Γ· 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) Γ 2 - (Door Width Γ 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.
Linear feet = square feet Γ 12 Γ· board width in inches. Widths shown are the actual face widths of nominal 1x4, 1x6 and 1x8 decking.
| Area | 3Β½ in boards | 5Β½ in boards | 7ΒΌ in boards | 5Β½ in +10% waste |
|---|---|---|---|---|
| 100 sq ft | 343 lf | 219 lf | 166 lf | 241 lf |
| 150 sq ft | 515 lf | 328 lf | 249 lf | 360 lf |
| 200 sq ft | 686 lf | 437 lf | 332 lf | 481 lf |
| 250 sq ft | 858 lf | 546 lf | 414 lf | 601 lf |
| 300 sq ft | 1029 lf | 655 lf | 497 lf | 720 lf |
| 400 sq ft | 1372 lf | 873 lf | 663 lf | 961 lf |
| 500 sq ft | 1715 lf | 1091 lf | 828 lf | 1201 lf |
| 600 sq ft | 2058 lf | 1310 lf | 994 lf | 1440 lf |
| 800 sq ft | 2743 lf | 1746 lf | 1325 lf | 1921 lf |
These are face-coverage figures and ignore the gap between deck boards. A ΒΌ in gap adds roughly 4% coverage on 5Β½ in stock, which the waste factor absorbs.