What is a linear foot?
A linear foot is simply 12 inches of length. Width and thickness don't matter. Trim, baseboard, fencing, gutters, countertop edges and lumber are often priced by the linear foot.
Two ways to calculate
From pieces: multiply the number of pieces by the length of each. Inches are converted to feet by dividing by 12.
From area: when you know the square footage you want to cover with boards, divide the area by the board's width in feet. The formula is square feet × 12 ÷ board width in inches.
Examples
- 10 boards at 8 ft 6 in: 10 × 8.5 = 85 linear feet
- 100 sq ft of shiplap with 5.5 in coverage: 100 × 12 ÷ 5.5 = 218 linear feet
Linear feet vs square feet vs board feet
| Unit | Measures | Used for |
|---|---|---|
| Linear feet | Length only | Trim, fencing, lumber by the piece |
| Square feet | Area | Flooring, tile, paint, drywall |
| Board feet | Volume of wood | Hardwood and rough lumber |
Converting lumber to board feet? Use the board foot calculator. Measuring a room for trim? The baseboard calculator takes doors out for you.
Frequently asked questions
How do I calculate linear feet?
Add up the lengths of all the pieces in feet. For 6 pieces that are 10 feet long, that's 60 linear feet.
How do I convert square feet to linear feet?
Multiply square feet by 12, then divide by the width of the material in inches. 50 square feet of 6-inch boards is 100 linear feet.
Is a linear foot the same as a foot?
Yes. A linear foot is 12 inches of length. The word linear just makes clear that width isn't counted.
How many linear feet are in a yard?
Three. One yard is 3 feet.
Results are estimates for planning. Product coverage, site conditions and installation methods vary, so check manufacturer guidance before you buy.