Linear Feet Calculator
Linear feet measures running length: trim, fence, gutter and railing are all priced this way. Calculate a rectangle's perimeter or add up separate runs, with waste included.
Result
- Linear feet104lin ft
- With waste114.4lin ft
- 8 ft pieces to buy15pieces
- Metric34.9m
How it works
lin ft = 2 × (length + width)
- Perimeter = 2 × (40 + 12) = 104 ft
- + 10% waste = 114.4 ft
- 8 ft pieces to buy = 15
How the linear feet calculator works
A linear foot is twelve inches of length, no matter how wide or thick the material is. It's the unit lumber yards use for anything sold by length: studs, trim, pipe, fence boards.
For a rectangle, the perimeter formula 2 × (length + width) gives the total run. For scattered pieces — several fence lines, multiple rooms of baseboard — add each run times its count.
Add a waste allowance before converting to pieces: 10% for straight runs with few cuts, 15% for trim work full of miters.
Formula
perimeter mode: 2 × (length + width) | runs mode: Σ(run × count)
Worked example: fence around a 40 × 12 ft yard
- Perimeter = 2 × (40 + 12) = 104 ft
- With 10% waste for cuts and corners = 114.4 ft
- 8 ft fence boards to buy = ceil(114.4 ÷ 8) = 15 boards
- Metric = 114.4 × 0.3048 = 34.9 m
Linear feet to pieces at common stock lengths
| Linear feet | 8 ft pieces | 12 ft pieces | 16 ft pieces |
|---|---|---|---|
| 50 ft | 7 | 5 | 4 |
| 100 ft | 13 | 9 | 7 |
| 200 ft | 25 | 17 | 13 |
| 400 ft | 50 | 34 | 25 |
Pieces = linear feet ÷ stock length, rounded up. Add waste before converting.
Frequently asked questions
What is a linear foot?
Twelve inches of length measured along the material, regardless of width or height. A 1×4 and a 1×12 that are each 8 feet long are both 8 linear feet, though they contain different amounts of wood.
How do I calculate the linear feet of a fence?
Measure the perimeter: 2 × (length + width) for a rectangular yard. A 40 × 12 ft yard needs 104 linear feet, or about 115 ft with waste — 15 boards at 8 ft for a board-on-board fence.
How do I convert square feet to linear feet?
You need the board width: linear feet = area × 12 ÷ width in inches. 200 sq ft of 5.5" boards is 200 × 12 ÷ 5.5 ≈ 436 linear feet (before adding the install gap).
How many 2×4 studs are in 100 linear feet?
It's the same 100 linear feet — linear feet already counts length. What changes is cost: at $3 per stud, 13 eight-foot studs (104 ft) cost about $39.