Carpet Calculator

How Carpet Is Measured and Sold

Carpet is manufactured in rolls — typically 12 or 15 feet wide. The width of the roll determines where seams fall in your room. A 12-foot-wide room can use a 12-foot roll with no seams. A 14-foot room will have a seam, and the waste from the narrow strip adds to your total. This calculator accounts for roll width in the linear footage estimate.

Carpet Padding

Carpet pad (underlayment) is required under virtually all broadloom carpet. It extends carpet life, improves comfort, and provides sound insulation. Standard pad thickness is 7/16 inch with 6 lb density for residential use. Premium pad (8 lb density) is recommended for high-traffic areas. The pad area matches the carpet area — the calculator includes this in the estimate.

The Bottom Line

Carpet estimating is mostly about managing waste from roll width and seam placement. A 13-foot room with a 12-foot roll means 1 foot of waste across the entire length, plus a seam. Work with your carpet retailer on seam placement — they'll diagram the layout to minimize waste and put seams in low-visibility areas. Get the square footage from this calculator, then have the retailer confirm the linear footage based on their specific roll width.