Display the total number of parcels as percentages for ArcGIS Pro

Summary

In ArcGIS Pro, when working with zoning files that display parcel data, the total number of parcels may be expressed in terms of percentage. Displaying the parcel count in the map legend as percentage data is useful for statistical analysis and land use planning.

To get the percentage of parcels in each zone, the values must be calculated and updated manually. The instructions provided describe how to display the total number of parcels as percentages when using a zoning table for ArcGIS Pro.

Procedure

1. Start ArcGIS Pro and open the project.
2. In the Contents pane, right-click the feature class and click Attribute Table to open the attribute table of the feature class.
3. Click Clear Selection to deselect all selected rows.
4. Right-click the target field and click Summarize.
5. In the Summary Statistics dialog box, configure the parameters.
   1. For Output Table, specify a name for output table to store the calculated statistics. In this example, the output table is ZONE_COUNT.
   2. For Statistics Fields, select the Field and Statistic Type drop-down menu to be calculated. In this example, ZONE_CODE and Count are selected.
   3. For Case Field, select the same field from Step 5(b).
   4. Click OK.

6. In the attribute table, right-click the target field and click Summarize.
7. In the Summary Statistics dialog box, configure the parameters.
   1. For Output Table, specify a name for output table to store the calculated statistics. In this example, the output table is ZONE_SUM.
   2. For Case Field, click Remove.
   3. Click OK.

8. In the Contents pane, right-click the stand-alone table created in Step 7 and click Open to open the table.
9. Take note of the sum of parcels calculated. In this example it is 195.

10. In the Contents pane, right-click the feature class, click Joins and Relates, and click Add Join to open the Add Join dialog box of the feature class.
11. In the Add Join dialog box, configure the parameters.
    1. For Input Field, select the same field from Step 5(b).
    2. For Join Table, select the stand-alone table created from Step 5. In this example, the stand-alone table is ZONE_COUNT.
    3. For Join Field, select the same field from Step 5(b).
    4. Click Validate Join to determine if the layer and table have valid field names and Object ID fields.
    5. Click OK.

12. In the attribute table, click Add to add a new field.
13. In the fields view, specify a name for the new field, alias, and set the data type to Double.

14. Click Save on the ribbon to save all edits to fields.
15. Return to the attribute table, and click the newly created field to highlight it. In this example, the newly created field is ZONE_PERCENTAGE.
16. Click Calculate to open the Calculate Field and configure the parameters.
    1. For Expression Type, select Arcade.
    2. Specify the following Arcade expression in the Expression section:

$feature['<fieldName>'] / <sumOfParcelsCalculated> * 100

$feature['ZONE_COUNT.COUNT_ZONE_CODE'] / 195 * 100

3. Click Verify to run a test of the expression. If the expression is valid, click OK.

The image below shows the total number of parcels as percentages in the attribute table.