Write down each room you plan to carpet. Sketch each room, breaking them own into measurable squares or rectangles.
Measure each room with the tape measure, using your sketch as a guideline. Write down the length and width of each square or rectangle.
Multiple the length by the width for each area measured. Add together all areas for one room.
Add each room's total area together in order to achieve a final sum for the carpet project. Divide this figure by nine to determine the total square yards of carpet needed for the project.