How to Calculate Carpet for a Room
- 1). Calculate the surface area to be covered in carpeting. Measure the length and width of the room and add 4 inches to both dimensions to allow for trimming. Multiply the length of the room by the width for simple rectangular rooms. The result is the area of carpet required. For example, a room with adjusted dimensions of 15 feet long and 10 feet wide requires a carpet area of 150 square feet: 15 x 10 = 150.
- 2). Break irregularly shaped rooms into multiple rectangles. For example, a rectangular room with a chimney breast in the center of one wall can be split into three rectangles: one each on either side of the breast and one for the rest of the room. Treat circular and elliptical window bays as rectangles with the length and maximum width of the bay area. Calculate the area for each rectangle and add them to find the total floor area.
- 3). Divide the total floor area by nine, the number of square feet in a square yard, because carpet is sold by the linear yard. The result is the number of square yards of carpet required for the room. For example, a room with a floor area of 150 square feet requires 17 square yards of carpet: 150 / 9 = 16.67.