Place the end of a tape measure at one side of the longest section of the planting site. Have another person hold it down, or set a brick or heavy object on top of it. Stretch the tape measure to the other end of the planting site to measure the total length in feet. Write down the measurement on a piece of paper.
Move the original end of the tape measure to the end on one of the shortest sides of the planting site and stretch it across to the other side to measure the total width of the site in feet. Write down this measurement as well.
Multiply the length measurement by the width measurement to arrive at the total square footage of the planting site. You may need a calculator to assist with this. At some sod manufactures, you will simply provide them with this square footage measurement to order your sod.
Divide the total square footage number by the 9, if the seller provides sod by the square yard instead of by the square foot. For example, if your total square footage is 1,000, divide it by 9 to arrive at 112 square yards of sod to cover the area.