Starting with ArcGIS Pro 2.2, the 'Calculate Geometry Attributes' geoprocessing tool was added to generate geometry attributes on a field. This tool can be accessed from within a context menu in the attribute table or the geoprocessing pane.
The instructions provided describe how to calculate geometry in ArcGIS Pro.
Access the Calculate Geometry Attributes tool by opening the attribute table and right-clicking the field to bring up the context menu. There is an option to 'Calculate Geometry'. This tool can also be accessed directly from the geoprocessing pane from within the Data Management toolbox.
Click Calculate Geometry to open the Calculate Geometry Attributes geoprocessing tool. The input features and selected field are already loaded into the parameters. The desired property to calculate from the field can be selected from the Property drop-down. It is also possible to calculate multiple Target Fields from this dialog.
Click Run. This calculates the selected properties for each feature and adds them to the selected fields.