The size of a roll of carpet varies according to its availability, with the most common length being 12 feet. Standard lengths of carpet rolls also include 15 feet and 13 1/2 feet.
The precise measurement of a carpet roll is typically not included in its actual sale measurement. This is due to the fact that rolls feature an additional 1 to 3 inches of additional carpet at their ends known as selvage. Selvage from the loom is included on rolls of carpet to ensure that the edges of the carpet do not fray or unravel during transport or installation.