Property is broken down into lots. These lots are most commonly rectangular in shape. Of common shapes, only a rectangle 's area is calculable by measurements of only the perimeter of the lot. Determining the acreage of a lot of land is also referred to as determining the area of the lot. People use the area of land for buying property to determine how much land they are buying. People can determine the area of the land with measurements of the perimeter.

Measure one side of the perimeter of the property, if the property is a rectangle. For example, one side of the property measures 20 feet.

Measure the side of the property that is not parallel to the side first measured. For example, the non-parallel side is 25 feet.

Multiply both measured sides of the property. In the example, 20 feet times 25 feet, which equals 500 square feet. One acre equals 43,560 square feet.