How to Calculate Square Yards for Carpet

Measure the length and width of the room to calculate the square yardage of carpet needed. Start the measurement in the center of doorways to allow the carpet to meet the floor covering in the next room, or simply add about 2 inches to each measurement. Be sure to measure the longest and widest areas of the room.

Draw a diagram of the room. Calculations will be easier if you are able to draw your diagram to scale. For example, use a scale such as one centimeter equals one foot. Be sure to include all doorways, closets, fireplaces and other built-in features of the room in your diagram.

Plan the layout of the carpet on your diagram. If the width of the room is less than the width of your chosen carpet then multiply the width of your chosen carpet, either 4 or 5 yards, times the length of the room. For example, say the room is 9 feet wide (3 yards) and 18 feet (6 yards) long. The actual square yardage needed is 3 yards x 6 yards, or 18 square yards. However, that would result in a seam down the center of your room. To avoid a seam, use the width of the carpet, 4 yards for our example, times the length of the room, 6 yards, and purchase 24 square yards of carpet.

Add 10 percent to the total square yardage needed when installing Berber or patterned carpets to allow for pattern matching during installation when a seam will be necessary.