Measure each room's length and width. Multiply these two figures to obtain the square feet for each room.
Include measurements for closets or other small spaces in a room. Measure these areas by their length and width, then multiply the figures to obtain the total square footage.
Sum the square feet totals for each measured area. The total of all areas represents the total square feet for the area to be carpeted.
Divide the figure from Step 3 by nine to obtain the total square yards for the carpet needed.