Carpet rolls are usually 12 feet or 15 feet wide and carpeting is often sold by the linear foot. For example, if you purchase linear 20 feet from a roll that is 12 feet wide, you will have 240 square feet of carpet. Likewise, if you buy 450 square feet of carpet from a roll that is 15 feet wide, it is equivalent to buying 30 linear feet.

 

A common question when carpeting a room is how many linear feet to buy, given the dimensions of the room and the width of the carpet roll. Since the width of the carpet is fixed, you will almost always end up with excess. The goal is to end up with as little excess as possible and thus to find the minimum length of carpet needed. You can use the carpet calculator to work out the correct length of carpet to buy, or use the equation given below.