Linear feet measure length only; square feet measure area. Material such as trim, fencing, fabric, tile edging and lumber is priced by the linear foot, while coverage — what a floor, wall or deck needs — is in square feet. Converting from one to the other always needs a second number: the width of the material. This calculator takes the length (or area) and the width in inches and does the conversion in either direction.
How to use the linear feet to square feet calculator
- Choose the direction: linear feet to square feet, or square feet to linear feet.
- Enter the amount you have or need.
- Enter the width of the material in inches. For flooring, use the face (coverage) width.
- Read the result and the calculation shown under it.
Linear feet to square feet formula
Linear feet = square feet ÷ (width (in) ÷ 12)
Dividing the width by 12 converts inches to feet, so the area is length in feet times width in feet. A 12-inch wide material is exactly 1 foot wide, so linear feet equal square feet. Anything narrower gives fewer square feet per linear foot, and anything wider gives more.
Worked examples
- 100 linear feet of 6-inch board: 100 × 6 ÷ 12 = 50 sq ft.
- Covering 100 sq ft with 3¼-inch strip flooring: 3.25 ÷ 12 = 0.2708 ft, so 100 ÷ 0.2708 = 369.2 linear feet, before adding waste.
- 250 linear feet of 5½-inch decking: 250 × 5.5 ÷ 12 = 114.6 sq ft.
Linear feet per square foot by width
| Width | Width in feet | Linear feet per sq ft | Linear feet to cover 100 sq ft |
|---|---|---|---|
| 2.25 in | 0.1875 | 5.33 | 533.3 |
| 3 in | 0.2500 | 4.00 | 400.0 |
| 3.25 in | 0.2708 | 3.69 | 369.2 |
| 4 in | 0.3333 | 3.00 | 300.0 |
| 5.5 in | 0.4583 | 2.18 | 218.2 |
| 7.25 in | 0.6042 | 1.66 | 165.5 |
| 12 in | 1.0000 | 1.00 | 100.0 |
Choosing the right width
- Nominal vs. actual. A 1×6 deck board is about 5½ inches wide; a 2×4 is 1½ × 3½ inches. Always use the actual width.
- Coverage width. Tongue-and-groove flooring and siding cover less than the board’s overall width because the joint overlaps.
- Gaps. Decking is laid with a small gap, which reduces coverage; add the gap to the board width to get the pitch.
- Waste. Add 5% to 15% for end cuts and defects, more for diagonal layouts.
Where it is used
Landscape edging, baseboard, crown molding and fence rails are bought by the foot. Fabric, vinyl and carpet are bought by the linear foot off a fixed-width roll, and the width tells you how much area you get. A fence is estimated by the linear foot of fence line, with the height as the second dimension. For lumber volume rather than area, use the Board Footage Calculator.
Start with the area of your space using the Square Footage Calculator, then convert it to boards. For decking see the Deck Flooring Calculator, for fences the Fence Calculator, and for floors the Flooring Calculator.
Frequently asked questions
How do I convert linear feet to square feet?
Multiply the linear feet by the width in feet (width in inches ÷ 12). 100 linear feet of a 6-inch board is 100 × 0.5 = 50 square feet.
How do I convert square feet to linear feet?
Divide the area by the width in feet. To cover 100 square feet with boards that are 3.25 inches wide you need 100 ÷ 0.2708 = 369.2 linear feet before waste.
Is a linear foot the same as a lineal foot?
Yes. Linear foot, lineal foot and running foot all mean one foot of length, regardless of width or thickness.
Why is the board’s real width different from its name?
Dimensional lumber and flooring are named by nominal sizes. For example, a 1×6 board is really 5½ inches wide. Use the actual width, or the covering width for tongue-and-groove, which is smaller than the board width.
What about square feet to board feet?
Board feet include thickness: 1 board foot is 144 cubic inches. See the board footage calculator for lumber volume.