How to use the linear feet calculator
- Add up pieces: enter each piece length and how many you need. Choose the length of boards you will buy.
- Read the total linear feet, the boards to buy and the cut list for each board.
- Square feet to linear feet: switch modes, enter the area and the actual board width.
Linear feet formulas
Linear feet = sum of (piece length in feet × quantity)
From inches: total inches ÷ 12
From square feet: sq ft × 12 ÷ (board width + gap, in inches)
Worked example
Shelving: 4 × 7' 6", 6 × 3' 2" and 2 × 11' pieces from 12 ft boards
- Linear feet = 4 × 7.5 + 6 × 3.167 + 2 × 11 = 30 + 19 + 22 = 71 LF.
- Cutting longest first with 1/8" kerf: 2 boards for the 11' pieces, 4 boards each with a 7' 6" and a 3' 2", and 1 board for the last two 3' 2" pieces.
- Buy 7 boards of 12 ft (84 LF); about 13 LF ends up as offcuts.
Square feet to linear feet by board width
| Board (actual width) | Linear feet per 100 sq ft |
|---|---|
| 2 1/4" (strip flooring) | 533 |
| 3 1/2" (1 × 4) | 343 |
| 5 1/2" (1 × 6 or 2 × 6) | 218 |
| 7 1/4" (1 × 8) | 166 |
| 9 1/4" (1 × 10) | 130 |
No gaps, no waste. Add both for decking and siding.
Common mistakes to avoid
- Using nominal widths. A 1 × 6 is 5 1/2" wide, not 6".
- Buying exact linear feet. Pieces rarely fit stock lengths perfectly; use the cut list.
- Ignoring kerf. Many cuts on one board eat inches.
Frequently asked questions
What is a linear foot?
A linear foot is simply 12 inches of length, measured along the piece, whatever its width or thickness. Trim, lumber, fencing and countertops are often priced per linear foot.
How do I calculate linear feet?
Add up the lengths of all the pieces in feet. 4 pieces of 7' 6", 6 of 3' 2" and 2 of 11' make 30 + 19 + 22 = 71 linear feet.
How do I convert square feet to linear feet?
Divide the area by the board width in feet, or multiply sq ft by 12 and divide by the width in inches. 200 sq ft of 5 1/2" boards with 1/8" gaps is 200 × 12 ÷ 5.625 = 426.7 linear feet.
How many boards do I need?
It depends on how the pieces fit into stock lengths. The cut list fits the longest pieces first and fills offcuts with short ones, allowing for the saw blade. The example needs 7 boards of 12 ft (84 LF) for 71 LF of pieces.
Is a linear foot the same as a board foot?
No. A linear foot is length only. A board foot is a volume: 12 in × 12 in × 1 in. Hardwood is sold by the board foot.