How to calculate the area, perimeter or length in ArcGIS?

Calculating the geometry of an entity is a fundamental geoprocess that must be known when starting with ArcGIS. To calculate the area or surface, perimeter or length of an entity is required to know the geometry of each layer. It is also recommended that each layer has an assigned coordinate system.

In the following process you can apply to calculate the area and perimeter in a layer of polygons. For polyline layers only the length can be calculated, and for XY coordinates (for projected coordinates select Double, and for geographic coordinates select Text).

For example, to calculate the area and perimeter of a polygon, right click on the layer select Open Attribute Table. In the attribute table in Table Options select Add Field. Assign a name (Area, Perimeter), and in Type select Double and accept the changes.

Now, right click on the required field header (Area) and select the Calculate Geometry tool. The geometric property (Area), the coordinate system, and the units (ha) you want to use are selected. To calculate the perimeter, the same process is repeated, but in this case the Perimeter property is selected.

With this process you can calculate the area, perimeter, length or coordinates of a shapefile (according to its geometry). It is important to remember that if changes in geometry are caused, the area, perimeter, or length fields are not updated automatically. Therefore, the fields must be recalculated after having made some geometric change in an entity.

While this is the easiest way to calculate geometries, there are also other options available in Field Calculator, Scripts, extensions or directly from ArcToolbox.