What Is a Linear Feet Calculator?
A linear foot is simply a measurement of length equal to 12 inches, regardless of width or thickness. When you buy flooring, decking, trim, fencing, or lumber that comes in fixed-width boards, you need to know how many linear feet to purchase to cover a given area. This calculator converts a total square-foot area into the linear feet of board you need, then optionally estimates the material cost.
How to Use It
Enter the total area you want to cover in square feet, the board width in inches, and (optionally) the price per linear foot. The tool converts the board width to feet, divides the area by that width to get linear feet, and multiplies by the price to estimate total cost. Add 5–10% extra for cuts and waste.
The Formula Explained
Because area equals length times width, the length (linear feet) needed equals area divided by width: $$\text{Linear Feet} = \frac{\text{Area (ft}^2\text{)}}{\dfrac{\text{Width (in)}}{12}}$$ Width is divided by 12 to convert inches to feet so the units match. Cost is then $$\text{Cost} = \frac{\text{Area (ft}^2\text{)}}{\dfrac{\text{Width (in)}}{12}} \times \text{Price (\$/ft)}$$
Worked Example
Suppose you are installing flooring over a 320 ft² room using boards that are 5.5 inches wide. The board width in feet is \(5.5 \div 12 = 0.4583\) ft. Linear feet \(= 320 \div 0.4583 \approx\) 698.18 linear feet. At $2.50 per linear foot, the material cost is \(698.18 \times 2.50 \approx\) $1,745.45.
FAQ
What is the difference between linear feet and square feet? Linear feet measure straight length only; square feet measure area (length \(\times\) width). This tool bridges the two using the board's width.
Should I add waste? Yes — most installers add 5–10% extra to cover cutting, mistakes, and pattern matching.
Can I use this for fencing or trim? Yes, anything sold by the linear foot. For trim, you can also just total the lengths of each run directly.
