# How Do You Calculate the Lot Size of a Property?

By Staff WriterLast Updated Apr 13, 2020 5:35:03 PM ET

To calculate the lot size of a property, sketch the shape of the lot, divide it into regular shapes, calculate the area of the shapes with applicable mathematical formulas, and add all the areas. Find the actual measurement of each property boundary first.

To determine the boundary dimensions, start by obtaining property documents such as the title deed and title report, which feature property boundary size descriptions and a plat map respectively. The plat map describes the relationship between the property and its nearest neighborhood, and the property boundary dimensions. In some instances, the map may indicate the size of the lot. You can obtain copies of such documents from the property seller or the office of the county recorder. Alternatively, you can obtain the boundary dimensions online by searching for them on the county assessor's official website if the municipality provides this information online.

Once you've obtained all the boundary dimensions, draw a sketch of the lot, and indicate the dimension of each boundary. Create regular shapes such as rectangles and triangles out of the sketch for easier calculation. Use a suitable measuring tool to measure any unclear dimensions, and fill in the values. Follow up by calculating the area of each shape, taking caution to apply the mathematical formulas appropriately. Finally, sum up the areas of all the shapes to get the size of the entire lot.

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