In most instances, the term "foot" refers to a linear foot. A linear foot is equal to 12 inches, or 1 foot. It isn't necessary to convert feet to linear feet because they are one and the same. If a board is 5 feet long, it is 5 linear feet. The term linear only applies to units of measure that are a straight line. Lumber, vinyl, fabric and fencing are typically measured in linear feet. Only the length is measured. Width is irrelevant for linear measurements.
Things You'll Need
 Measurement tape
Calculate Linear Feet

Make sure that the item you are measuring is a straight line.

Measure the length of your item in inches. Do not include the width of your item in your measurement because the width is not relevant to linear feet.

Convert the inches to feet by dividing the total number of inches by 12. The result is equal to the linear feet of your item.
Tips & Warnings
 The perimeter of a room or a fenced area is often measured in linear feet. To arrive at the total linear feet of a room, take the measure all four walls and add them to obtain the linear feet.
 The same measuring principles apply to linear meters and yards.
 A linear foot is not the same as a square foot. Square footage is calculated by measuring the length and the width of the item and multiplying the two. To calculate the square footage of a room 18 feet long by 10 feet wide, you would multiply 18 by 10 to get 180 square feet.
References
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